Not a bad ending, but I would've loved to see how they handle someone who actually enjoys it.
The engines on the transport rumbled as it neared the landing pad, thrusters rotating as it slowed its forward movement and settled down roughly on the metal platform. A cadre of armed guards approached as the ramp dropped, revealing a motley crew of prisoners. The youngest among them was Tanya, a girl barely out of her teens with short black hair with blue forelocks, wearing the orange jumpsuit she was given after her arrest mere days prior. She fancied herself an artist, but the police of were the belief that her works were fomenting sedition against the planetary government. She was convicted, sentenced to trial, and shipped off to the newest of the prisons.
For an oppressive autocracy it wasn't much to look at. There were guards, certainly, and high fences surrounding the pad and leading towards the massive, Brutalist ferrocrete structure, but the prison itself had no security to speak of, seemingly unwalled in an open field of dry grass. What was more, several figures - presumably prisoners - in strange dark outfits were milling about outside of the building, making no attempt at fleeing. A myriad of possibilities filled her mind, and she resolved to be on her guard for any escape opportunities.
The prisoners shuffled single-file through the entrance under the watchful eye of security cameras until they reached three widely-spaced man-sized shutters. Square platforms rose from the ground and prisoners were ushered onto them, whereupon manacles rose up and latched around their ankles. The shutters opened and the platforms slid into into inky blackness, the prisoners disappearing as the shutters closed again and another platform appeared to take its place.
When her turn came up Tanya regarded the platform with a mixture of distrust and curiousity, until a guard gave her a shove onto it with her rifle. Immediately the manacles latched into place and the door opened before the platform jerked into motion, carrying her past the threshold. Once she was in the space beyond the door smoothly closed, leaving her in darkness.
A second later she was lit from all sides by lights whose origins she couldn't pinpoint. As she raised one hand to shield her eyes her body was suddenly doused by a spray of clear fluid. There was a light tingling across her skin but no harm came to her. Her clothing was less fortunate, falling apart and dissolving, running off her body with the rest of the fluid and leaving her nude.
She made a move to cover herself, only for two more manacles to descend from the darkness, latching around her wrists and pulling her arms to the sides. As she struggled a second spray hit her from all sides, thick and cold, running along her limbs before coating her body in a matte black, leaving only her hands, feet, navel, backside, and crotch exposed. The substance quickly solidified and grew snug on her body, gaining a light sheen. The sprays performed a second pass around her waist, building up and creating a short skirt that barely covered her exposed parts. A collar clamped around her neck from behind, and a thin laser descended from the darkness, etching a series of numbers into the material above her left breast.
The lights turned off, plunging her into darkness, and as she wondered what was to come she felt something cold press firmly against her navel. There was a loud hissing, and her entire body ached for a few moments before subsiding. The platform lurched into motion again as a door opened in front of her, and the manacles retracted, leaving her to stumble into the prison's bare antechamber, filled with the other, similarly dressed new arrivals that came before.
Tanya shook off her daze to take stock of her outfit. The material was shiny and tight but not painfully so, and quietly squeaked and creaked with every move she made. There were no seams or zippers which, combined with the strategically-placed openings, made her believe that it was never intended to be removed. She hesitated to call it "comfortable" - regarding anything at all in a dystopia as being pleasant or acceptable was the first step to being broken, she reasoned - but it was certainly a far cry from the rough cloth of the jumpsuit. Perhaps if she wasn't being forced to wear it as part of her punishment for dissenting she would have-
She shook her head, trying to push the thought out of her mind. A door to the outside opened and guards encroached on the fringes of the group. The prisoners, taking the hint, went outside.
The warden was a severe-looking middle-aged woman; it wasn't until Tanya saw her that she realized that all the guards in the prison were women. She stood at one of the balconies overlooking the outside of the prison, addressing the prisoners in the field below. "Welcome to Correctional Facility RM-771," she proclaimed. "You have, through your own actions and choices, volunteered to test the security features of this prison."
"Doubtless, you have noticed the uniforms put upon you when you entered. It is an application of the armor our military uses, designed to resist pressure." There was a quiet murmur from a few of the other prisoners. "When you arrived, after the uniform was placed upon you, you were filled with gas."
She blinked. -Filled with gas?- Was that even possible? She could have been lying, but what reason did saying something so patently unbelievable serve? The thought that they simply strung her up and filled her from a nozzle like a balloon when she arrived made her feel... she didn't really know what she felt, honestly. A particularly vivid image entered her mind, and with some difficulty she forced it away.
"Now," the warden continued, pointing beyond the prisoners, "you'll notice a line along the ground encircling the facility. That is the range of the collars placed upon you. You have free reign of the facility, but should you cross that line, the collar will activate, removing the suit. That suit is the only thing keeping the pressure of the gas in check, and without it, you will expand and thereby be immobilized." She paused, letting the prisoners mutter among themselves. "It is not harmful - if we wanted you dead we would have executed you - but it is unavoidable."
Tanya touched one hand to her chest, trying to feel the gas inside of her through the suit, imagining how much it would take to expand someone to the point where they couldn't move, and what kind of shape they would take. The thought was becoming more and more intriguing to her as time passed.
Suddenly one of the prisoners turned and sprinted away. None of the guards made a move to stop her, and the warden simply said impassively, "excellent. We have a volunteer."
The guards and prisoners watched as she ran, nearing the line. The moment her foot crossed it her suit simply broke apart into strips, and time seemed to slow for Tanya as she watched the pressurized gas find release. At first her thighs and breasts swelled, giving her an exaggerated hourglass figure before her belly grew to the scale of pregnancy. They then grew thicker, her arms joining in as the sheer speed of her growth forced her arms up. Her back rounded, the curves of her sides disappearing as her body pushed outward in all directions, limbs growing shorter even as they fattened themselves. In the span of a second the would-be escaped convict was a flesh-toned sphere with hands, feet, and a head, her breasts pulled across her surface and faint contours where there were once physical features.
It was the most amazing thing Tanya had ever seen.
The prisoners looked on as the escapee simply rocked back and forth on her stomach from the momentum stunned into silence for a second before flapping her arms and feet and crying out in frustration. The guards made no show of urgency as they sauntered towards her.
"You cross the line," the warden said, "and that happens to you next."
One by one the prisoners returned their attention to the warden, save for Tanya. She watched as her fellow convict struggled in vain, swollen and inflated with gas, trapped by her own body and reduced to utter helplessness. Her eyes followed her as the guards pushed her back towards the prison, hands brushing against every inch of her skin and pressing into her taut flesh as she bounced and rolled along the ground.
"If you keep pushing your luck, you will be left like that until a time when we see fit to return you to normal. Eventually you will learn your lesson."
The guards gave the ballooned prisoner a shove, forcing her through a doorway a size too small for her. Tanya's chest ached, filled with a need she barely understood.
"That is all."
The warden turned and disappeared from view, leaving the prisoners to their own devices. Some went back inside, other sorted out into groups to meet with old friends and associates. Tanya remained in place, coming to grips with her new situation and her new feelings, losing track of time in her daze.
Eventually she shook it off and, without much hesitation, she took a step towards the line.