Author's Note: Many thanks to Bethany (Handcuffgirl) for her edits and suggestions.

This story is a sequel to The Gym, though it could be read on its own.

You'll notice a distinct similarity to Susan's Exercise Bike, posted by Green Particle quite recently. I swear this is not just blatant plot plagiarism. I wrote the entire story and sent it to Bethany for editing before Green's story was posted - you can verify with her if you want! I was a little dismayed to see that my idea would not longer be original, but then figured, hey, great minds think alike. Green Particle - keep up the good work!

Amy wanted to lose weight. She wanted it bad. While she wasn't actually overweight, she was definitely heavier than all her skinny friends, and she was tired of their subtle looks of disapproval. Even more, she hated the feeling that she was the second-tier choice when they all went out together trolling for guys.

Everyone told her that she was crazy, because she was in fact a very attractive girl. Her shoulder length, caramel-brown hair framed a face that was as cute as a button, and her creamy, smooth skin covered curves that her friends said they would die for. Amy, however, knew better. All excess weight had to go.

The problem was that Amy just couldn't seem to find the motivation to do any kind of strenuous work out. She had all the motivation in the world when she was planning her runs, but the moment she got tired that motivation would disappear. Searching the internet for solutions, she didn't hesitate to lay down a big chunk of change on a new, high-tech treadmill that she thought might help - the Acme Pro-Form 9000.

This treadmill was designed to help runners achieve the perfect running form. A camera mounted on the front of the machine, as well as cameras mounted on the extended handlebars along both sides of the tread belt, allowed a built-in computer to monitor and analyze a runner's movements. If that runner's knees weren't being lifted high enough, or their posture began to slump at the end of their workout, then a red light would illuminate on the treadmill's console and a message would scroll across its screen identifying the problem.

Amy read that professional runners loved these treadmills, as they were able to monitor form far better than any human trainer could have. Video analysis could do the same thing, but the immediate feedback from the Pro-Form 9000 was much more useful. Amy also read that amateur runners got a lot of benefits from the treadmills. Plenty of studies showed that poor running form could lead to injuries and even long-term joint problems. For herself, Amy just hoped that the constant feedback would help encourage her to keep going for more than just a few minutes at a time.

To her dismay, Amy quickly found that the treadmill's feedback had no effect on her tired self. The annoying red light would come on and the machine would tell her that she was leaning too far forward or was dragging her feet. The tired girl would simply give up and pout on her couch until she got mad at herself and tried again, but her efforts always quickly ended in failure.

After a particularly frustrating workout attempt, the morning after an equally frustrating night out with her friends, Amy was bothered by the loud barking of her neighbor's dog. They ought to get that damn dog one of those shock collars, she thought. Then a new idea hit her. It was crazy, but she was desperate, and she thought it just might work.

Amy was no electrician, but the re-wiring she needed to do turned out to be quite simple. The dog collar she had purchased came with a remote that had a button to deliver shocks at the owner's command. Pulling off the plastic cover, it was clear that all the button did was connect two wires which then sent the signal. The red light on the treadmill console was equally simple; the machine sent current through two wires to illuminate the light whenever a mistake was noticed. By connecting the wires from the button to the wires from the light, Amy's treadmill would send a shock to the collar if the perfect running form was not maintained.

Testing the collar around her own neck proved without a doubt that the shocks would maintain her motivation. The narrow leather collar fit snugly around her throat. From a small box on the front of the collar, two metal prongs poked into the skin on either side of her wind pipe. The prongs were a little annoying, but not terribly uncomfortable. That is, unless those prongs were delivering a shock, in which case they hurt like hell.

Amy's original plan was to strap the collar around her neck, set a half-hour jog program, and let the machine shock her if she tried to stop. She knew those shocks would be quite painful, but she was desperate to find a way to force herself to exercise and was willing to go to this extreme.

For the first couple minutes of her first collared workout, Amy jogged with the perfect running form to avoid unnecessary shocks. Unfortunately, just like before, the moment her body started to get tired she lost all motivation. When her foot dragged and her collar shocked her, instead of lifting her knee as she should have, she ripped the collar from her throat and threw herself onto her couch.

Ten minutes into her pout, Amy re-gathered her reserve, vowing to find a way to force herself to exercise. Placing a padlock through the clasp of the collar was a simple and effective way to prevent easy removal. Another lock had to go around the front of the collar to prevent the batteries from being removed. Preventing herself from hitting the stop button on the treadmill console was trickier. After a bit of searching, however, she found just what she needed. The plate of plexiglass wasn't cheap, but it fit perfectly over the console, making it impossible to access any of the buttons.

The hardest part was devising a way to keep the plexiglass plate locked down during her workout, then make it accessible once she was done. Amy hit on a solution when she noticed a white light on the console that stayed on while a workout program was active, then turned off once it was finished. She bought a little electric lock and tied it to that white light the same way she had tied the collar remote to the red light. With the lock powered on, the plexiglass would be locked down from the inside for the duration of any workout. Then when the lock lost power, the plate would be released.

Amy figured she had planned for everything and was excited to finally lock herself up for a long workout. She locked the collar around her neck and placed her only key on top of the console where she wouldn't have access to it until the end. Taking a deep breath, she programmed a half-hour jog and pressed the plexiglass cover down, locking it in place.

Unfortunately, it turned out that Amy's tired-self was quite resourceful. The moment she got tired, she simply ran to her kitchen and cut her collar off. Once rested, she was furious at herself, and able to find a shock collar that was specifically designed for dogs that tried to scratch or rip them. The leather was three inches wide and much thicker, and had an inner band of metal that would be impossible to cut through without serious tools. It fit quite snugly around her throat, but would not hamper her breathing.

Tired-Amy next discovered that she could simply unplug the treadmill, causing the shocks to stop and the console glass to be unlocked. Rested Amy was annoyed that she hadn't thought of that ahead of time, but was able to build a locked box that prevented any access to the cord or outlet without a key. Just to be sure, she put that key and any tools that might assist in her escape in her basement. She even left her cell phone in the basement to prevent her tired self from cheating by calling for help. She then padlocked the basement door and put that key under the plexiglass along with her collar key.

The final curve-ball that tired Amy threw was the discovery that running out of range of the remote control would prevent shocks from being delivered. She could simply run into her backyard and rest there for the duration of the workout. To overcome this, Amy had to upgrade her collar once again, to a version that was just as thick and unbreakable, but also included an option for an invisible fence. She made sure to buy the kind that would deliver a continuous shock if the dog moved beyond a predefined boundary. Setting that boundary within just a couple feet of the treadmill ensured that she would not be able to move out of the remote control's range.

Amy was sure that she had finally eliminated all escape routes. She would still be able to run outside if her house caught on fire, though she'd be subjected to a continuous shock until someone arrived with a heavy-duty bolt cutter to free the collar from her neck. Barring a fire or something equally life-threatening, tired-Amy would have no option but to complete whatever workout rested-Amy programmed.

After two minutes of her first truly non-optional workout, Amy started searching desperately for a way out. She tried to just stop and rest, but the pain from the shock collar made that impossible. With no option to remove the collar or stop the machine, she had no choice but to get back on the belt and run.

Having never made it past those first couple of minutes, the running girl was surprised to find just how sensitive the Pro-Form 9000 could be. Apparently it started out by only identifying big flaws like dragging feet, but then continued to get more and more detailed in an effort to guide the runner into the perfect form. In Amy's case, of course, 'guide' was the wrong word. She was forced to adopt the perfect form, or the sensitive skin of her throat would pay the price.

The first correction the treadmill made was to the height of her knees. Without warning, pain seared through her neck and the words Lift your knees higher scrolled slowly across the machine's console. In normal operation, the red light and the instruction would be a gentle reminder to the runner to make the form correction. In Amy's case, it was an unavoidable command, with the first punishment dealt out before she even had a chance to respond. She had already received half a dozen shocks while trying to escape and was desperate to avoid any more. Lifting her knees felt more tiring, but she quickly obeyed.

Land mid-foot, not on your toe or heel, read the console as Amy received yet another shock. She screamed at it to stop, though she knew full well that the machine had no ability to receive voice commands. Landing on the middle of her foot felt odd, and it took her a number of paces to get it right. While concentrating on her foot placement, the treadmill punished her for once again for not raising her knees high enough. The girl screamed in frustration, but redoubled her efforts at getting the form right.

The number of intricacies involved in perfect running form was far greater than Amy had expected. She was forced to maintain excellent posture, not leaning either forward or back. Her shoulders were to be held back and also kept relaxed. Her head had to be held up, but not so far that her chin jutted out. Hands were not to be clenched, but rather her fingers had to lightly touch her palms. While she had always swung her arms across her body when she ran, the treadmill forced her to swing them forward and back, maintaining about a ninety-degree angle and staying between waist and lower-chest level.

Through all of the pain and aggravation that accompanied the forced adoption of a perfect running form, Amy couldn't help but notice that she was becoming sexually aroused. She wasn't exactly sure about the cause. It could have been the knowledge that the treadmill's cameras were inspecting every part of her body so closely. Or maybe it was the fact that a machine had complete, inescapable control over her. Hell, it could have just been endorphins from running or adrenaline from the pain she kept receiving. She couldn't focus too much thought on the quandary as she continued to concentrate on honing her form, but neither could she ignore the fire that was steadily growing in her loins.

By the end of her half-hour workout, Amy had made it through all of the fine points of perfect form that the treadmill had to offer, though she was still not able to accurately perform them all together for more than a few moments at a time. When the program finally ended, she quickly lifted the plexiglass, grabbed the key to her collar, and yanked the prongs away from her throat.

Her next order of business was to finally do something about the fire in her pussy. It had continued to grow through all the shocks and the exhausting workout, and Amy simply couldn't wait any longer to plunge her fingers into her panties and do something about it.

During that first workout, Amy had sworn that she would never again turn control over to the infernal treadmill. The pain had been unbearable, the workout had been exhausting, and... and, shit, it had been everything she had hoped for, and more! That kind of workout would definitely get her in shape. The pain had seemed too intense, but upon inspecting her neck she found that no permanent harm had been done. On top of everything, the unexpected sexual pleasure sealed the deal. She would definitely be coming back for more.

The very next day, Amy found herself standing on the treadmill, locking the collar around her neck. Muscles all over her body were protesting, but she ignored them - getting in shape was going to involve some pain. Speaking of pain, the nerves in her throat definitely protested when they felt the metal prongs press into her flesh. She had thought about trying to reduce the intensity of the shocks or move the prongs to another part of her neck, but decided against it. A strong incentive was clearly necessary to maintain motivation. She was just going to have to get stronger and improve her form.

Five minutes into the workout, Amy was sure her plan had been a mistake. Correct form seemed even more difficult to maintain with muscles that were already tired and sore. After ten minutes, however, she felt as if she crossed some kind of line into a zone where she could do anything. She'd never felt so good, and was finally able to maintain form for more than just a short moment.

A full minute went by without Amy receiving a single shock. Then, without thinking she had slipped up, pain seared into her throat. She glared at the screen to see what she had done wrong and was quite irked to read, Good job, you have achieved your first minute of perfect form!

The red light was not, of course, designed to be a punishment. Rather, it was intended to draw the runner's eyes to the console to read a new message. Amy had just been punished for her success. The thought was maddening, but also served to stoke her sexual fire. It reminded her that she was not in control. The treadmill could shock her even if she did everything right. It could shock her whenever it wanted to and for whatever reason, and there was nothing she could do about it.

Amy wondered about her apparent love of being under control. She'd never considered herself to be into bondage or anything similar, but she could no longer deny the source of the fire. She started looking forward to her forced workouts as much for the sexual experience as for the shape they were getting her in. Amy even started wearing skimpier outfits, enjoying the knowledge that the cameras would be able to see more of her bare skin. Without putting a name to it, she began to think of the treadmill as her master. That master owned her body during the workouts; she could only do her best to try to please him, and accept any punishments he decided to dole out.

On one fateful Friday a few weeks in to her new running routine, Amy cued up a sixty minute workout, her longest yet. She would be put through four cycles of fifteen minute runs, with short walking breaks in between. As usual, she donned her skimpiest running clothes. The flimsy shorts barely covered her ass and had slits along both sides that went all the way up to her waist band. The sports bra provided support to her large breasts, but did not cover up any more skin than was absolutely necessary to accomplish its task. Her socks did not extend beyond the heel of her shoes, so that as much of her long legs could be left bare as possible.

The final step, as always, was to lock the shock collar around her neck. The feel of the wide, heavy leather pressing into her skin never failed to send shivers down her spine. The press of the metal prongs into her throat was not entirely comfortable and served as an unavoidable reminder of the punishment that could come at any time. Closing the lock on the back of the collar was the point of no return. The only key was already locked under the plexiglass and the program was already set to begin in a matter of seconds. With one little squeeze, that program went from optional to mandatory. Click! Amy was again at the mercy of her treadmill.

The running girl went into a trance-like bliss during the first fifteen minute segment, interrupted only by the occasional shock when the treadmill notified her of an encouragement message or the very rare event that she misplaced a step. Once she had mastered the proper form and wasn't making mistakes, she had thought that the encouragement messages would start coming at the same intervals. The treadmill, however, was not that predictable, so she never knew when she might get a blast from the prongs in her throat.

One of those unpredictable shocks came at the start of her first walking break. She grimaced, then glanced down to see what message of encouragement her treadmill-master was giving her. To her surprise, the screen simply read, Kink Mode.

Eric got out of prison with a lot of ideas but also a lot of caution. He had spent the last five years of his life in the slammer for the tricks he had played on girls at the gym he used to own. That was five years too many in his opinion, and he had no intention of ever going back.

Shortly into his prison term, a number of companies who manufactured bondage equipment had gotten in touch with Eric. They wanted to tap the genius designer of the machine they had read about in the news, and the inmate was more than happy to oblige. With nothing better to do with his time, he cranked out designs for an impressive number of new contraptions for the companies to produce and sell. As a former business owner, Eric made sure to sign favorable contracts with those companies, which meant that by the time his sentence was up, he had become a rather rich man.

With his newly acquired money and freedom, Eric could easily afford to live a life of comfort and luxury. With the contacts he had made, he could also certainly find some woman who shared his love of bondage. Unfortunately, he didn't have much interest in either of those things. It was the concept of tricking unsuspecting hotties into humiliating situations that really got him going. Another prison sentence was out of the question, but so was giving up his passion. His conclusion was that he would just have to avoid getting caught.

Eric struggled to find a way to engage his passion without the risk of discovery. The problem was bringing together girls and gear in a way that couldn't be traced back to him. He spent a long time brainstorming and web surfing before he finally found an existing machine that just might help: the Acme Pro-Form 9000 treadmill.

The horny ex-con read about how the treadmill was supposed to help both professional and amateurs with their running form. As a former gym owner, he certainly appreciated a fine gait, but of much greater interest were the three cameras that watched the runner from the front and both sides. The crowning feature, in Eric's mind, was the fact that the treadmills came with built-in wireless internet connections. This allowed users to download new workouts and share progress with friends. It also allowed Eric to hack his way in, using a backdoor that Acme had created to service the machines. Once hacked, the treadmills provided live video from the cameras that captured every angle of the running bodies on their belts.

Over the following month, Eric did nothing but observe. He found a wide variety of people using the treadmills - men and women, old and young, fat and thin. Fortunately for him, the brand had become quite popular, giving him his pick of cute girls to watch. He was quite happy to find that even more girls wore skimpy outfits in the privacy of their own homes than in a public gym. One chick, who he watched whenever possible, would come into view of the cameras in her work clothes and just strip down to her undies to exercise.

The voyeuristic aspect of watching all the long bare arms and legs pump up and down without their owners being aware of his presence was quite exciting to Eric, but he knew he needed more. Even when he got to see bare, toned tummies and nicely shaped tits and asses, it just wasn't enough to only observe. He started writing new workout routines and loading them onto the treadmills of the girls he found most attractive. Starting subtle so as not to get noticed, he did things like slowly adjusting the knee position higher and higher and requiring girls to hold their shoulders further and further back.

Eric got a couple girls into full-on prances, with their shoulders back and their tits thrust all the way out, before they decided something must be wrong and called the company to investigate. Whenever that happened, he erased the code he had added and completely severed his connection with that machine so that he couldn't be found and the company would have no reason to really look.

The former gym-owner got a real kick out of commanding all these babes without them even knowing it. He still yearned for more, however, until one day he found an opportunity that seemed too good to be true. A genuine jackpot. Her name was Amy.

Kink Mode.

Amy stared at the console of her treadmill, slowly coming out of the trance-like bliss that she slipped into whenever she ran under the control of her machine. She had just finished the first fifteen-minute segment of a newly programmed sixty-minute workout, and she had no idea what the message meant or how it had become part of her new program. Perhaps it was an option that she just hadn't read about, or some new feature that had been downloaded, and maybe she had hit some wrong button when she had set up the workout. In any case, there was nothing she could do about it at that point.

Lift your knees higher, the console read after she received another shock.

Amy obeyed, but apparently still wasn't stepping high enough, as she got another shock and the message was repeated. The message had to be repeated a third and fourth time before the treadmill was satisfied. By that time, her knees were coming most of the way up to her chest, and the walk had become a ridiculous march.

Clasp your hands behind your back.

That command was easy enough to follow, but the order to squeeze her elbows closer together had to be repeated three times until the new program was content. Her elbows felt like they were nearly touching, and the position definitely caused an ache in her shoulders. That ache was nowhere near as severe as the pain she got blasted with when she tried to relax her arms, so she obediently held them in place.

The effect her arm position had on her breasts was not lost on the marching girl. Her big boobs were pressed outward, stretching against the fabric of her thin sports bra. She certainly understood why this program was called 'kink mode,' though that didn't help her understand how it could have been activated. It was as if her treadmill master had come to understand the sexual pleasure she was getting from her workouts, and was toying with her. She was being forced to show off her long legs in front of his eyes, and thrust out her chest towards him. That idea was of course ridiculous, but she couldn't help but think it was true, and it definitely turned her on even more than normal.

At the end of the break, the program reverted to the second fifteen-minute run segment as expected. Everything was normal, except perhaps for the extra wetness in Amy's pussy. The girl couldn't help but be a little worried about the fact that the treadmill had activated a program that she was not aware of. She had no way to alter that program while the unbreakable plexiglass was locked over the console, and no choice but to follow whatever the program commanded for remaining forty-five minutes. That thought definitely got her going even more, at the same time that it made her nervous.

Remove your sports bra.

That command, at the start of the second rest period, took Amy completely by surprise. The treadmill was supposed to offer suggestions about how she moved, not what she wore! She waited a moment, then was hit with another shock and hoped to see a different message on the console. The command to remove her sports bra was repeated. She still delayed in her confusion, but after a third repetition, it became apparent that the program would simply keep it up until her bra was removed. The shocks from her collar were, as always, impossible to ignore, so the baffled girl went ahead and ripped off the garment.

"Fine!" she shouted at the inanimate machine. "You want to see my tits? Here they are!"

The treadmill simply responded by ordering her back into the high-knee march with her hands clasped behind her back and her elbows nearly touching. The thrust of her breasts was even more obvious now that there was nothing holding them back. Amy's arousal reached new limits as she marched along topless, thinking about the master that had forced her to bare her chest.

Through the haze of Amy's lust-filled mind, a disturbing thought poked through. She wondered how it was even possible for the treadmill to determine whether or not her tits were covered, and how it knew that she had been wearing a sports bra in the first place. The cameras and programming were designed to carefully monitor movement, not to identify the presence and type of clothing. Did that mean that there was a real person watching her through the cameras?

The thought that someone might be watching her kinky march made her flush with embarrassment and jump off the treadmill away from the cameras. The shock to her throat was instantaneous, and she knew without looking that the console would be telling her to resume her marching. She tried to resist, and even thought for the first time in ages about how she might escape. There were no outs, however, as she well knew. She could run away, but the continuous shock would very quickly drive her back to the treadmill, given that there was not actually any life-threatening emergency within her house.

Back on the treadmill, Amy was more aware than ever of the cameras that had a full view of her long bare legs and her now naked boobs. The thought that some unseen stranger might be watching her through those cameras was absolutely mortifying, and made her hornier than ever. The concept of the treadmill as her master was no longer an abstract fantasy. If there really was someone watching her, and if that person was able load programs onto her treadmill, then they did indeed have complete control over her body. Jesus, they'd be able to see her pussy leaking if she kept thinking about it!

When the third running segment started, Amy made a dash for her bra and pulled it over her head, thinking that the decency would be worth the couple of shocks she would get while off the treadmill. Unfortunately for her, the first correction message she received once she started running was to again remove the bra. She had no choice but to complete the running segment topless, her boobs bouncing all over the place. She tried to hold or cover them, but as always the perfect running form required that her arms only move forward and back, and stay at about waist level. Anyone looking was getting a full show of the bouncing orbs, and there was nothing she could do about it. All she could do was worry and get wetter as her mind and her pussy anticipated what might come during the next break.

Remove your shorts.

Amy couldn't be too surprised when that command came at the beginning of her final break. She was not, however, expecting it to be followed up by a command to pull her panties up into the crack of her ass. Whoever or whatever was behind the command was not satisfied until her panties were completely buried, fully exposing her two round globes and pressing firmly against her pussy.

Marching in this state really got the poor girl going. She didn't even bother looking down to confirm that she was dripping right through her thin panties. Looking would have only caused another shock, and she could feel the wetness anyway. Essentially her entire body was on display for whoever was watching. She was convinced that it was indeed some guy behind the cameras, and she was giving him the show of his life.

When the final run segment began, she knew there was no point in trying to retrieve her shorts, or pulling her panties out of her crack. She just obediently completed the run, her butt cheeks bouncing in time with her tits as her long bare legs pumped up and down.

At the conclusion of the run, the exhausted girl reached for the console cover so she could finally free herself and end her embarrassment. Instead, she got another shock and read, Time to stretch, on the screen. She tried one more time to retrieve her clothing, but was only shocked and told to remain on the treadmill. The stretching, apparently, had to be done in the near-buff.

The first stretch involved standing sideways on the treadmill, spreading her legs wide, and bending over as far as she could. It was certainly a good hamstring stretch, but Amy didn't miss the fact that it also gave one of the side cameras an excellent view of her ass. When another shock came, Amy had to stand up to see the console, and was quite irked to read the message, Continue holding this stretch.

"I already would be if you hadn't shocked me!" Amy shouted, with no expectation that anyone could hear her even if there was someone watching her.

When the next shock came, Amy thought she would try staying bent over, but a second shock in quick succession made her look up. She was being instructed to stretch her arms by holding on to the two side rails and leaning forward as far as she could. Just like the last stretch showed off her ass, this stretch meant that she was thrusting her chest right in front of the console camera. She wished her nipples weren't so damn hard as she did this. She also wished the treadmill would finally let her touch them.

By the time the stretching routine ended and Amy was finally set free, she was in such a sexual heat that she pleasured herself before she even bothered unlocking her collar. Later that afternoon, just thinking about the experience she had been through sent her into another masturbation frenzy, as it did again later that night.

Amy tried to find the program that had been triggered, but as far as she could tell there was nothing different about the machine and there was no "kink mode" in any of the menus. She thought about reporting the incident to the manufacturer, but she was sure she would never be able to handle the embarrassment of having to admit how she had modified the treadmill. No matter the origin of the kink mode, the predicament had essentially been her fault. Instead of calling, she just stayed off the treadmill and kept the shock collar well away from her neck.

As the days passed, however, Amy couldn't take her mind off the treadmill. She had been doing daily, forced workouts for weeks. The lack of exercise started getting her down, as did the lack of the unique kind of sexual stimulation she had been getting from the machine. She tried using the treadmill without the collar or the locked console, but quickly found that it just wasn't doing it for her. As before, she gave up the moment she got tired, and there was nothing stimulating about just simple jogging anyway.

By the end of the week, Amy decided she had to try something. She put the collar on, but left herself a key outside the console. Pretending that she was under the control of the machine, however, did nothing to force her to exercise or recreate the sexual experience. The desperate girl even tried lining her workout room in a steel mesh in an attempt to cut the treadmill off from its wireless internet connection. The connection was blocked, but she found that the treadmill wouldn't even turn on unless it was connected, which was supposedly some kind of safety feature that couldn't be disabled.

Finally, two weeks after the kinky incident, Amy decided that she simply had to get back to her old routine. To try to minimize the risk of anything crazy happening, she made plans with a friend to come over to her house at six PM, then started a half-hour jogging program at five. If everything went normally, she would have time to shower and change before her friend arrived. If, on the other hand, she lost control to the machine, hopefully her friend could help.

Being again under the control of her treadmill definitely turned Amy on. For the first time in two weeks, she was able to push herself past two minutes of jogging. Her muscles loved the work and her pussy loved the captivity. Her mind continued to worry that something might happen, though when the workout ended normally and on-time, she did feel a small amount of disappointment.

The next two times Amy worked out, she made similar plans with friends. When nothing out-of-the-ordinary happened, though, she began to again turn her body over to the machine without any failsafe. After a dozen more workouts passed without incident, she stopped worrying altogether and even started wondering if her brain had made up the whole thing to begin with. There was no hard evidence that anything had gone wrong, and the idea that her treadmill could have gone so haywire just seemed so far-fetched.

On a Saturday morning, a few weeks after she had returned to her workouts, Amy was excited to lock herself into a longer run than she had yet tried. She wanted to give herself a full two hours, which felt like a significant landmark. Stripping down and pulling on her skimpy running outfit, she sealed her keys behind the console cover and closed the padlock around her collar. That was always the point of no return, but she had stopped being overly worried about it.

Kink mode.

The appearance of that message at the start of her first break sent shivers through Amy's spine. She was terrified at the same time that she was incredibly excited. Had she been hoping this would happen again? Right at that moment, it would have been impossible for her to answer that question. She was again under the control of either some rogue programming or an actual person who had hacked her treadmill's computer. She had no idea what was going to happen, and that very thought was turning her on like crazy.

The anxious girl wondered for a moment if she should try to get help. Her cell phone was locked in her basement, so finding help would require running to the house of her nearest neighbor, hoping they were home, and hoping she could explain the problem through the searing pain her collar would be delivering. As always, and by design, there was no way Amy would be able to convince herself to attempt such a thing unless her life was actually being threatened. Barring that, she was stuck right where she was.

Right off the bat, messages on the console ordered the Amy to strip out of her sports bra, shorts, shoes and socks. She was left naked except for the panties that she had to again pull far up her crack, and of course the collar that would not be coming off her throat. The break continued with the same high-legged marching as before, leaving her mind to worry and fantasize about what else might happen in future breaks, since this first break had already gone as far as she had gone the last time. Actually, she had gone even further if she counted the removal of her shoes and socks.

When her next running segment began, Amy was immediately hit by a shock. The confused girl knew she was performing the running form correctly, and was surprised to see the console tell her to lift her knees higher. She had to keep bringing them higher until she was lifting them nearly as high as she did during the kinky march, and the new commands didn't stop there. Her arms had to be crossed behind her back, each hand holding the opposite elbow. She had to land on her toes, and her feet were to remain pointed the entire time she was in the air.

Learning this new running form was at least as difficult as learning the original. Amy was getting shocked constantly for one small infraction or another. She wanted to hate what was being done to her and the pain it was causing, but she couldn't deny the arousal she was feeling. Showing off her body like this, and being completely out of control to an unknown force, was exactly what turned her on the most.

Place the treadmill's failsafe clip over your left nipple.

This message, at the start of the next break, left Amy a little confused. The treadmill had come with a standard clip that a runner was supposed to attach to their clothing so that if they fell, the belt would automatically stop. Amy had disengaged that failsafe long ago, and thought she had gotten rid of the clip. Sure enough, however, she found it sitting in one of the cup holders. Receiving another shock, she quickly closed the clip over her nipple as instructed.

The break period continued with Amy again marching with her arms held behind her back, now with the added discomfort of her tender bud being crushed between the teeth of the clip. Amy had never felt anything like it. Even when a boyfriend squeezed her nipples, he never did it this tightly or for this long, and his fingers weren't made of hard plastic. It definitely hurt, but it also turned her on, perhaps because she enjoyed that kind of pain or perhaps because she was helpless to avoid it.

Do you enjoy the nipple clip? Nod or shake your head.

The marching girl was confused to read this for a number of reasons. It was the first time the console had ever asked her a question. Could it really understand her reply? Did that confirm there was a real human behind all of this, or would the machine just be able to read the movement of her head in the same way it could monitor the rest of her movements? On top of that confusion, she really wasn't sure whether the answer was yes or no.

Your delay implies that you don't hate the clip. Find a clothespin within your house and place it over your right nipple.

Amy watched this message scroll across the screen with incredulity. Was her treadmill really going to force her to go find another implement with which to torment herself? Just leaving the treadmill would mean going outside the invisible fence defined by her dog collar, which would trigger a long and painful shock. As if in answer, her throat received a shock, and the screen read simply, Go.

The trapped girl knew she had no choice. She would get shocked if she went, but she would just continue to get shocked if she didn't go. Fortunately, she knew just where she kept a bag of clothespins in her kitchen. It was incredibly humiliating to have to sprint to her kitchen and back, naked but for her panties and collar, getting shocked the whole way, all so that her tormentor would have yet another tool with which to hurt her.

As soon as Amy was back on the treadmill and had both her nipples clamped, her break ended and she was commanded to resume the high-knee run. It was really more of a prance, she decided, and it made her boobs bounce like crazy. That had been bad enough during the last running segment when she was topless. Now it was even worse with the clamp and clothespin getting an extra tug with each bounce.

The prancing run was also considerably more tiring than her usual run. Amy was very ready for the next break by the time it came, though she had to worry about what more the treadmill had in store.

Find a vibrating dildo and bring it back here.

Amy didn't need a second shock to send her sprinting to her bedroom and back with the required device. The horny girl was certainly mortified at the thought of using a dildo in front of a camera, whether or not someone was watching, but she knew she had no choice and couldn't deny that her pussy wanted some attention anyway.

Remove your panties, turn the dildo to its lowest setting, and insert it into your pussy.

Losing her last piece of clothing made Amy feel even more vulnerable than before. It also raised her arousal far enough that she almost orgasmed the moment she pushed the vibrator through her lips.

Resume marching. If you allow the dildo to fall, you will be punished.

Keeping the little vibrator inside her dripping pussy was no easy task. She got a shock if she tried to use her hands to stop it from slipping, and the high-legged march provided plenty of motion to help shake it out. Clenching her muscles was only making her all the more horny, and the resulting flow of juices eventually made her lose her grip. She was expecting her punishment to be a shock to her collar, which did arrive, but only to announce the next message.

Hold one end of your clothespin. Slap your tit hard enough to knock the pin off your nipple.

Amy couldn't believe what she was reading. That was going to hurt like hell! For a while she thought she would just accept the collar shocks instead, but after only three shocks she changed her mind. Better to get the one pain over and done with than continue to get the other pain for who-knows-how-long.

The first slap she gave herself hurt both her boob and her nipple quite a bit, but didn't succeed in knocking off the clothespin. She also received a shock for the failure, which really irked her. With her second slap, she made quite sure to knock the clothespin off, grunting from the sting of her slap and from the blood rushing back into her bud.

With one nipple free and aching with renewed blood flow, Amy was ordered to reinsert the dildo and begin to prance once more. It was even more difficult to hold the slippery little toy inside at the faster pace. Every time she landed, the device was shaken downward, and it took a herculean squeeze of her vaginal muscles to try to push it back up. She did eventually get the hang of it, but not until she had been punished with a command to slap the clip off her other nipple and deliver hard spanks to her own ass.

Prancing while naked and vibrated was keeping Amy right on the edge of her orgasmic cliff. She was desperate for the workout to end at the same time that a part of her hoped it would never end. All she could really hope for was that when the current segment was complete, she would finally be given some release.

At the beginning of the next break, Amy received another shock from her collar and glanced at the screen to read, Bend over the right-side handrail. Pull the carabineer clip from under the treadmill and affix it to the ring on your collar.

The hazy-brained girl obeyed immediately. Bending over the bar to her right, she reached down and pulled out the carabineer, then clipped it onto the ring that extended from the front of her collar. Only then did she pause to wonder why there was a carabineer clip underneath her treadmill. She hadn't put it there, and there was no good reason that it would have come with the machine, which meant... HOLY SHIT! - someone had been in her house!

As the commands had become more elaborate, Amy had become more and more convinced that there was indeed someone watching her through the treadmill's cameras. This thought was mortifying, especially while trying to clamp her pussy muscles down on a dildo as she pranced in the buff. However, the fact that whoever was behind the cameras had actually been inside of her house changed the situation completely. He could come back!

Amy scrambled to unclip the carabineer from her collar, but was distraught to find that it would not come undone. The clip was attached to the underside of the treadmill by a short, metal cable. Tugging on that cable got her nowhere. She was locked securely to the machine, naked and with no clothing within reach. Her sense of vulnerability skyrocketed.

At that point, Amy thought she would have been able to convince herself to accept the shocks that would come from running outside to get help. She was no longer just exhibiting her body through the treadmill cameras for some theoretical stranger. Some man could be on his way to her house at that very moment. For all she knew, that might well be a life threatening emergency, but by that point her sole escape hatch had been sealed. She no longer had the option of leaving the invisible fence boundary even if she could muster the will power.

A shock hit Amy's collar, snapping her brain away from the potential future problems it was dwelling on and back to her immediate predicament. In her position, she had no way of seeing the treadmill screen, but the person who had set this all up had solved that little problem. A computerized voice came from somewhere beneath her, instructing her to pull a metal box out from under the treadmill. She did this reluctantly. The existence of that box only gave more proof that someone had been in her home without her knowledge.

The contents of the box made Amy's heart skip a beat. An array of bondage equipment greeted her. She'd never used many of the items, but they were recognizable enough. Though her pussy seemed excited to try them, her mind still would have thrown the box and its items out of reach so that she couldn't be forced to use them without the carabineer first being removed. Unfortunately, throwing the box would be impossible. It was secured to the underside of the treadmill, and each of the items inside were secured to the box with various lengths of thin cable.

Spread your legs and use the zip ties to secure your ankles to the vertical poles that support the handlebar, announced the computerized voice.

Amy really didn't want to do this. In her position, she figured she could at least flip over the bar and have use of her arms and legs. She would still be naked, tethered, and shock-collared, but she thought that she'd at least have some ability to defend herself. If she followed the command to tie down her ankles, then she'd be stuck over the bar, with her ass up high, and she'd lose her ability to kick.

The frightened girl resisted for a record five shocks before finally giving in. She told herself that she could have withstood more, but that it was pointless given that she could no longer even run away and that the painful shocks would surely wear her down at some point anyway.

The vertical poles were four feet apart, forcing Amy to spread her legs wide so that her ankles would reach. In that position, her belly was pressed firmly against the bar that she was bent over and her legs were held straight. She had to stretch to reach each ankle, but once there the zip ties went on easily enough. They were made of thick plastic and ratcheted shut with ominous sounding clicks. She knew they would not be coming off nearly so easily as they went on. Shit, who was she kidding - they would not be coming off until someone else cut them off for her.

Place the ball gag in your mouth and strap it tightly behind your head.

Amy had recognized the ball gag for what it was when she first saw it, but somehow hoped against hope that she wouldn't have to use it. Now that she was sure that her mystery tormentor would be paying her a visit, she truly did not want to lose the ability to speak. Unfortunately, that was not up to her, and she knew it. She didn't bother waiting for another shock before opening wide and stuffing the large rubber ball behind her teeth.

The taste of rubber filled her mouth as the ball pushed her tongue firmly down. It felt even bigger than it had looked, and was certainly going to prevent her from forming coherent words. As if to ensure that, the voice shocked her twice as it told her to tighten the strap further and further, then finally told her to secure a padlock through the locking hasp.

Insert the butt plug into your ass.

The bound girl had never inserted anything into her ass. The thought that she was about to do it sent shivers up and down her spine. The plug didn't look all that big to her, but she was comparing it to the dildos she had used in her pussy. She quickly found out that her rear hole was much smaller than her front. Her sphincter would have to stretch a good bit in order to accommodate the plug.

The humiliation she felt as she slowly pushed the device further into her ass was off the charts. The camera along the left-side handrail had a perfectly clear view of her long, spread legs and her bare ass and pussy. Someone was watching her violate her own butt. To her great dismay, this thought only stoked her arousal further. She tried to push the plug in quickly so as not to give her tormentor any more of a show than she was already giving. Unfortunately, the stretching got painful if she tried to go too fast. Moving slower, she actually found herself enjoying the sensation, though she did her best to hide it.

Next up, Amy was ordered to lock a wide belt tightly around her waist, then pull a strap from the front of the belt through her legs and attach it to the back of the belt. That strap also had to be pulled quite tight, pushing the butt plug even further into her ass. The lock that she was forced to closed through the strap and belt ensured that she would not be removing the plug on her own accord. The computerized voice also reminded her that she had just locked her own vibrator inside her pussy. The trapped girl felt like a fool for not thinking to remove it. Her mind had been such a chaotic jumble of humiliation and arousal that she had completely forgotten about the little toy.

The leather hood that had to go over her head seemed at Amy's first glance that it would be one of the easier items to accept. She had worn Halloween masks before, and didn't think it would be a big deal, so she quickly pulled it over her head to avoid any unnecessary shocks. Only once it was pulled down did she notice that the hood had no eye or mouth holes. The only openings were two small grommets near her nostrils. The bound girl's world was thrown into complete darkness.

To make matters worse, the hood was form fitting and tight. By the time she got the zipper all the way down in the back, the leather was pressed firmly into her face and scalp, and pushed her ball gag even further into her mouth. The feeling was unmistakably erotic, but it worried Amy as much as it turned her on. She wouldn't even be able to see whoever was coming for her, a fact she ensured by obeying the command to lock the zipper closed.

The last instruction Amy was given was to close a pair of handcuffs around her wrists. She had to feel around in the box for the cuffs, and felt that they were attached to the box by a very short cable. Closing them around her wrists would force her to bend over and stretch down even more than she already was, and it would keep her hands completely out of the way of her naked body. She would be able to do absolutely nothing to prevent or even hinder someone from doing anything at all to her helpless flesh. That thought caused sparks to fly from her pussy. Her unintentional delay caused another shock to hit her throat.

The computerized voice gave no more commands after ensuring that Amy had closed the cuffs tightly around her wrists. All the trapped girl could do was stand there and wait. Of course, she wasn't exactly standing. She was bent in half, with her legs spread and her ass held up high. She knew she was making quite a sight, even though she could no longer see herself. Talking had also been rendered impossible, with the combination of gag and hood rendering her incapable of voicing anything but grunts and moans.

Feelings of vulnerability and arousal washed over Amy in tandem. Her mind dreaded what might be coming at the same time that her that her pussy hotly anticipated at. She willed her pussy to cool down, but even without the vibrator that continued to buzz away on its low setting, that would have been completely impossible.

Every sound Amy heard through her hood was magnified in her head until it turned into the man who was coming for her. After what seemed like hours, she finally heard a scratching sound that definitely could have been someone picking the lock on her back door. In the silence that followed, she convinced herself that it had been yet another false alarm. Then her whole body jump as a loud full-belly laugh hit her ears.

At first, the trapped girl didn't know what to make of this laughter. Was it a good sign? Had this all been some kind of crazy prank? Then she recognized a distinctly maniacal tone. No, this was definitely not good. That was confirmed when two strong hands grabbed the sides of her hooded head.

"You stupid cunt," a deep voice accused from mere inches away. "Look at the mess you've gotten yourself into!"

One of the big hands reached around to grab her right breast. As it squeezed hard, mauling her tender flesh, Amy knew that this man was not going to quickly free her from the mess that she had indeed gotten herself into.

Eric really could not believe that his plan was going as well as it was. He had thoroughly enjoyed toying with Amy the first time he had electronically invaded her little self-bondage exercise adventure. Watching her bouncing boobs and her bare ass cheeks really would have been good enough for him. After he ended that first session, he was sure the girl would never use her treadmill again.

When Amy began to slowly work her way back onto the treadmill, Eric knew that he had to get involved again, and up the ante in a big way. It took him many days of planning, programming, and building, then more days waiting for the perfect moment to sneak the little box and carabineer clip into Amy's house. All that work had paid off in spades. Amy had gone back to her little self-bondage workouts, and after giving her a couple weeks to think that everything was normal, he had struck.

Eric was standing behind an incredibly hot and completely helpless woman. Amy might have thought that she needed to lose weight so badly that she had to literally bind herself to her treadmill, but in the former gym-owner's eyes, she was just perfect. The smooth curves running from her ample breasts down to her wide hips really got him going. Her long legs and arms looked great as well. The body part that really did it for him, though, was the soft, round ass that she was unwittingly proffering up to him. In his opinion, that thing could start wars.

The true source of Eric's arousal, however, was the feeling of power that coursed through his veins. The naked girl bent over before him was completely under his control. He had tricked and forced her into binding herself up like this, and now he could do whatever he wanted to her without fear of interruption or retribution. She had no idea who he was. The hood locked over her head ensured that he would remain anonymous. That hood also served to take her identity away. She was a faceless piece of meat, strung up for his consumption.

After running his hands all over the beautiful, soft skin of his prize, Eric brought one hand down in a hard slap onto the ass that so enthralled him. He watched the flesh ripple and enjoyed the resulting flex and surprised grunt elicited from the hooded girl. A hard slap to the other cheek produced another grunt, less surprised but just as enjoyable.

The girl beneath him tried to wiggle out of the way as Eric continued the spanking, but her position made that completely impossible. He certainly enjoyed the show, and wondered if Amy was enjoying it as well. She had, after all, set up the shock collar all by herself, and her reaction to the nipple clamps had been anything but clear.

Once the round ass was nice and red, Eric pulled a key out of his pocket and unlocked the crotch strap that ran between Amy's legs. This produced a whole new series of shakes and grunts from the girl, as did pulling the dripping dildo out of her pussy.

"Oh, were you enjoying that?" Eric mocked his captive. "How about this instead?"

He began stroking Amy's pussy lips and rubbing her clit. The bound girl let out a loud moan. Eric's feeling of intoxicating power grew stronger yet. Whether she wanted to respond or not, he had the power to force a reaction from her body. He resumed his spanking while he continued his stroking, causing ever more sensuous moans and frantic wiggles.

In short order, the sex-pot under his control was thrashing in an uncontrollable orgasm. At that point, Eric could hold himself back no longer. He pulled on a condom and plunged himself all the way into the dripping-wet pussy before him. While he pounded, he proceeded to pinch and roll the girl's sensitive clit in his fingers. He also resumed spanking her shining-red ass, and quite soon had thrown himself over the orgasmic edge as well.

Packing away the used condom so as not to leave any identifiable evidence, Eric told Amy that he was going to get himself a drink from her refrigerator and have a look around her place. Before he left, he re-secured the crotch strap, ensuring that the butt plug would stay in place until he got back. The girl grunted in displeasure through her gag, but did not and could not actually complain. All she could do was stand there and wait for him to return.

Amy listened as her mystery assailant walked out of the room. She was left, stuck in her awkward position on the treadmill, in complete darkness, as the man went off to rummage through her house. Though he had just given her the craziest fucking of her life, she had absolutely no idea who he was. All she knew, and all she would probably ever know, was the sound of his voice, the size of his strong hands, and the length of the cock he had used to pound her pussy harder than she had ever been pounded.

As she slowly came down from her orgasmic high, the throbbing from her well-spanked ass became more prominent and her mind began to worry once again. What was the man doing in her house? Stealing things? Breaking things? She felt so vulnerable, trapped there while he did whatever he wanted with any of her possessions. Then she had to chastise herself for worrying about the little things. She was still tightly bound, hooded and gagged, naked, and completely helpless. Forget her possessions, that man could do anything he wanted with her body!

Amy was sure that her body couldn't possibly handle any more stimulation. She wanted to think that the intruder must surely be satisfied as well, but then her ass reminded her of the butt plug that was still buried there. No, he wouldn't dare... would he? With her red ass held up high, her legs spread wide, and that monster stretching her sphincter muscles, Amy knew that she wouldn't be able to put up even an ounce of resistance if he did decide to fuck her there. The thought mortified her, and to her dismay, started to rekindle her desire. Why did her body have to keep reacting like this?!

After an eternity, Amy heard the man walk back into the room. Her body tensed involuntarily, and he laughed at her. He came over to talk to her, and through the nostril holes of her hood, she could smell that he had been drinking. That definitely did not bode well.

"I'm going to take some pictures of you with your camera," the man told her. "You'll be able to see just how hot you look, bent over and vulnerable like this."

Getting photographed was a singularly humiliating experience, trapped and helpless as she was. That was nothing compared to the humiliation she felt when the man removed her crotch strap and began to toy with the plug buried in her ass. Were her worst fears coming true?

Then she felt a large dildo being pushed through her pussy lips. She screamed into her gag, desperate to tell him that she couldn't handle any more stimulation. To her horror, as the dildo made its way all the way in, she recognized the feeling of two rubber ears pressing onto her clit. He was using her largest, most powerful, rabbit vibrator. That thing had the ability to drive her crazy in seconds under normal circumstances. Over stimulated as she was, it would surely drive her insane. She tried frantically to wiggle out of the way or convince him not to hit the on switch, but to no avail.

Amy's world exploded as the rabbit vibrator jumped to life. She almost didn't notice the stretching sensation as the butt plug was yanked from her ass. She could not help but notice, however, when her assailant placed the tip of his dick at the front of her hole. There was nothing she could do to prevent him from sliding his way inside. Her stretched sphincter muscles couldn't even put up a fight. Worse, her body was so high from all the stimulation she was getting, that she couldn't tell anymore what was stoking her fires. Her whole body was ringing, and the pounding of her ass fit right in to that picture.

After an undeterminable amount of time and an undeterminable number of orgasms, the man finally finished and removed both his dick and the vibrator. Amy was still panting through her nostrils and slowly drifting down off her high when she felt the man fiddling with her collar, then felt the cable holding her wrist-cuffs down to the box go slack. Thinking she was finally getting released, she just waited, only to feel her wrists get tugged over her head to the back of her neck. By the time she started to struggle, both cuffs had been secured to the back of her collar.

The naked girl tried to take better advantage when the zip ties around her ankles were cut, but the man was in front of her where she had no ability to kick. When she felt her collar cable get released, she stood up as fast as her tired body would allow and tried to run off the treadmill. She had no idea where she would go, still naked, hooded, collared and cuffed, but she figured she had to at least try something.

Before Amy even got off the treadmill, a giant tug to her collar halted her momentum. Pulling again, she determined that she was tethered by some new cable to the machine. She had a little more room for movement, but no more actual freedom. Still, she tugged and twisted and tried to get the new cable in her hands so she could pull on it. Then she got hit by a painful shock from her collar.

Stand still, came the computerized voice that she knew all too well.

It took a couple more shocks before the girl, who thought she had tasted freedom, was convinced that she did indeed still need to obey.

Hold your elbows straight out.

Amy was really not happy about having to obey the stupid computerized voice while the man who had just fucked her ass was standing there watching. Couldn't he just tell her what he wanted? And what more could he possibly want from her anyway?

New shocks and new commands continued until the naked girl was standing tall in the middle of her treadmill, her legs slightly spread, her posture perfect, and her elbows held straight out from her head. Somehow, standing like this in front an unknown man was far more embarrassing than being bent over and locked down in front of him. She was just as naked, just as helpless, but now she had the theoretical ability to move, even if any movement meant searing pain.

"You truly are a submissive slut," the man said.

Amy shook her head slightly to deny the charge, only to receive a shock and have the computerized voice tell her to keep her head facing straight ahead. She wanted to deny the charge, but she couldn't speak and she couldn't move. All she could do was stand still, showing off her naked body and acting the part of a submissive slut, just as he accused. Even to herself, she was having trouble denying the charge. Sure, she didn't have any control currently, but she had been the one who had set up this whole machine, and she had been getting off on everything she had been forced to do. Even standing like this was making her feel hot. A shiver ran through her body, and the man just laughed at her.

"Now," he said, "I've got to be going. You're going to have to stay on your treadmill for a while longer to give me time to get away. I made sure you'll be here for long enough that I can get home and watch through the cameras as you free yourself. I'm putting the keys to all your new gear under the console cover, so when the program ends you'll have access to all of them. It's not going to be terribly easy, sorting through the various keys while blind and trying to use them with your hands trapped behind your head, but I'm confident that you'll figure it out eventually and I'm sure you'll give me a good show in the meantime."

Amy could only grunt in dissatisfaction as her captor laid out his plans. Unfortunately, he wasn't even done.

"To keep you entertained," he continued, "I'm going to leave you with these nipple clamps. They're a lot sturdier than your clothespins, so you should find them quite impossible to shake off."

The standing girl mentally cursed the man as he rolled her sensitive buds back to hardness and closed the sharp-feeling teeth of the clamps over them. When he grabbed her first nipple, she tried to kick him, but he was standing to her side and she couldn't see anyway. All it earned her was another couple shocks, a firm swat to her sore ass, and having to hear the man call her a submissive slut again once she was back in compliance.

"I'm going to give you the choice of what gets hung on your nipple clamps," the man said as if he was being nice. "Little bells or fishing weights. The bells will be lighter, but their sound might get annoying. Grunt once for the bells and twice for the weights.

Amy didn't want to give the man the satisfaction of playing his game, so kept her silence. However, when he told her that she would get both the bells and the weights if she didn't chose, she gave up her pathetic little resistance and grunted once. The thought of any additional weight on her nipples sounded unbearable, so the bells seemed the obvious choice.

"In case those bells aren't enough entertainment, I'm also going to let you decide whether you want your vibrator while I'm gone or not. Just moan if you want it."

The over-stimulated girl was sure that she did not want the vibrator. However, the man began to tell her to picture herself naked and helpless, and wondered if she wouldn't get bored without her toy. To top it off, he began stroking her clit, which on top of the mental picture elicited an involuntary moan.

"Great!" he cheered. "I knew you were a slut!"

Amy tried to grunt and dodge as the big rabbit was pushed back into her well-used pussy. She didn't try very hard though. Her lack of effort may have been due to the shocks that dodging around would cause, or it may have been the futility of struggling with this man, or, to be honest, deep-down she might have actually wanted the vibrator back where it belonged. She just couldn't be sure.

With the crotch strap tightened and the vibrator buzzing away at its lowest setting, the man asked Amy what kind of workout she wanted while he was away - marching, prancing, or running. The exhausted girl had only expected to have to stand there for some period of time while her captor got away. The thought that her physically and sexually exhausted body would have to do even more exercise was horrifying. She tried to make a whimpering sound through her gag, hoping against hope that the man might take pity on her.

"I know," he told her as he stroked her abused left ass cheek, "so many good options! I figured you'd have a hard time choosing, so I programmed in a mixture of all three. It's a little bit longer, but I'm willing to wait the extra time so you can have some variety."

Amy grunted loudly and even accepted a shock while stamping one foot. She really didn't want any more exercise, and definitely would not have chosen a longer mix. Let me chose again! she wanted to scream.

"Oh, you might be worried about being tethered by your neck while you work out," the man said. That wasn't what she had been trying to communicate, but now that he mentioned it, it was a concern.

"Don't fear," he continued. "The cable is on a retractable spool. If you fall, it will extend far enough to get you off the treadmill, but not much farther. That will ensure that you don't try to do anything crazy like run outside, naked and hooded as you are."

Amy whined into her gag. She really didn't want any more exercise. Couldn't he tell what she was trying to communicate?

"I know, I know," he said, stroking the side of her leather-covered head. "I'll miss you too. But don't worry, I'm going to stay for a little longer so I can make sure that I programmed the new movements just right - they each had to be modified due to the position of your arms, you know. And don't worry about the batteries in your shock collar dying while you're trying to master the new form - I put fresh ones in there before I let you up."

The misunderstood girl tried to whine louder. It still didn't work.

"Look, I'm not going to give you anything else today, you insatiable whore! But if you want more another time, just keep locking yourself into your machine, and if you're lucky, maybe I'll come back."

With that, Amy felt the belt start to move beneath her. The first shock came quickly, and the computerized voice ordered her to lift her knees higher. Whining was clearly getting her nowhere, so the dismayed girl started up the high-legged march that she had become so good at. She thought she was good at it, anyway. The position of her arms threw off her balance, and the inability to see was extremely disorienting. She stumbled all over the place, and got plenty of shocks for it.

Even knowing it was futile, the desperate girl tried whining at her captor. This time he correctly interpreted the whine as a plea for leniency, though he gave her none. Instead, she felt a sharp slap to her very sore ass and had to listen to him admonish her to try harder and not be such a whiny brat.

Amy was mad and humiliated and getting horny again, all at the same time. This obscene march had been bad enough when she was alone and able to see. Now, being blind and knowing that someone was standing right there watching her made everything worse.

Prancing while blind turned out to be even more difficult than marching. She stumbled all over the place, generating shocks from her collar and laughter from her audience. Running turned out to be the easiest, though it sure felt as if the pace had been increased and Amy wasn't at all sure how long she would be able to keep it up.

After a few minutes at each pace, Amy was reverted to marching and felt her tits getting squeezed as the man said his final goodbyes. She was left alone with her treadmill once more. That was somewhat of a relief, except that she had no idea how much longer she would be forced to march, prance and run. The jingling of the bells on her nipples quickly became infuriating, and the slow buzzing of the vibrator locked in her pussy soon began to drive her to distraction.

Most infuriating, however, was that Amy couldn't stop thinking about the man's offer to return. How arrogant! How ridiculous! When he had said it, she had wondered why on earth he had thought she would even consider wanting him to come back. He had tormented her, humiliated her, and... and... he had driven her to new erotic heights that she hadn't even known existed. She also couldn't deny that by locking herself back onto her treadmill after the first time the "kink mode" had hit, she had essentially been asking for more trouble. The question was, if she survived the rest of her current ordeal, would she ask for it all over again?