An Unfortunate Experiment

“Thank you for agreeing to take part in this test, Miss Gelling,” Doctor Mitchell’s voice echoed, sounding tinny through the cheap intercom. The research budget was cut shorter each year – they had no funding to waste on a more expensive system. “It’s much appreciated.”
Mina Gelling smiled tentatively at the glass side of the chamber, trying not to feel nervous as she watched the small team of doctors just beyond.
“It’s no big deal, Doctor. I trust in your work.” That much was true. Over the past few months she’d been a research assistant here, she’d watched this exact same test performed on all manner of animals, from mice to chickens to pigs, and ever time the results had been exactly as predicted.
“I appreciate your faith,” Doctor Mitchell replied, her own tone almost as anxious as Mina’s, “We’re making history here – if Halen C proves safe for human contact… well, we may have literally solved world hunger. Instant, safe weight gain in any animal… I’ll get a Nobel, you’ll get a promotion, and this facility will actually have funding once again.”
Mina laughed, trying to ignore the butterflies in her stomach.
“What’s ten pounds when so much hangs in the balance? Come on – let’s get this make history.”

She lay back on the bed, controlling her breathing as she stared up at the ceiling of the hyperbaric chamber. She’d seen this test performed a thousand times – it was perfectly safe. She’d be out of this chamber in ten minutes time, ten to fifteen pounds heavier, perhaps, but otherwise none the worse for wear. Perfectly safe.
“Alright, I’m going to begin injecting the substance…” Doctor Mitchell’s voice rang through the intercom, “Starting at 0.005…”
There was a slight hiss, and immediately, instinctively, Mina’s breath caught in her throat. She forced herself to relax and to breathe; she had to inhale the gas for it to be effective. Perfectly safe.
She breathed in, tasting the Halen C in the back of her throat as it slid down into her lungs. It tasted faintly of vanilla, and almost at once she felt something change. Her body began to feel warm, heat radiating out from her backside, chest, thighs, belly – anywhere that there was a significant deposit of fat. It wasn’t painful; indeed, it was almost pleasant, a comforting warmth surging through her body, making her face flush red.
And then she felt herself begin to grow.

Beneath her loose top her stomach quivered, bulging slowly, subtly forwards, and she stared down at it with amazement. Despite all her experience with the animals, it was entirely different watching her own body shift before her eyes, however subtly. Forgetting for a moment the doctors watching her from beyond the hyperbaric chamber, she pulled up her top and watched with astonishment as her belly pushed slowly further into the air, pure fat shivering into life just beneath the pale skin.
It wasn’t just her belly either – she could feel her thighs thicken subtly as the weight slid quietly onto her body, feel her upper arms softening a little. She even felt her bra tighten gently as her breasts swelled half a cup size or so in a matter of moments, the underwire beginning to dig a little as her chest expanded.

“Incredible!” she heard the doctor’s voice through the intercom once again, and Mina tore her eyes away from her changing body, face breaking into a grin as he spoke, “Halen C has proven to react entirely as expected. We’ll need a full examination to be sure there haven’t been any side effects, of course, but this is extremely promising. Purging the chamber now; we’ll have you out in a minute, Miss Gelling.”

Mina heard another hiss, louder this time, and immediately a powerful taste of vanilla caught in her throat. She spluttered, smacking an elbow against the glass as she coughed, eyes widening. What the hell?
“Seal failure, seal failure!” she heard someone’s shouting – not through the intercom this time, but muffled through the glass, “The tank’s emptying into the chamber!”
It was already too late to hold her breath. Her lungs were full of Halon C, and a moment later it began to make its presence known. Her body scorched with warmth, waves of heat pouring through her from her fatty areas, and at once those areas began to expand. Her belly bulged forwards, far faster than before, thickening and softening before her eyes. Her navel creased as fat bunched up above and below it, her stomach slumping into two pale, quivering folds of flab that swelled larger with every second. Behind her, she felt her backside expand, filling out her sweatpants in an instant as her hips and thighs thickened with a soft new drapery of fat.
She had to get out of here. Struggling to her knees as her body ballooned around her, Mina tried urgently to push the chamber open, but it was clamped tight shut. She slammed her fists against the glass, feeling her upper arms beginning to shake and jiggle more and more as they surged plumper.

“Get her out of there!” she heard Doctor Mitchell, her voice sounding dim through the glass and the haze of her panic, “Open the chamber!”

Beneath her top Mina could feel her bra tightening around her chest, cutting into the new folds of flab appearing beneath her arms and on her back. Far beyond worrying about modesty, she yanked her away and tried urgently to unhook it, to free herself, but the clasp was already mangled and her newly-fattened arms and fingers were too clumsy to compensate. She wheezed, leaning back as the pressure built higher and higher, and for a moment she thought she was about to die, crushed by her own underwear – then the strap broke with an audible snap, her suddenly-flabby breasts spilling forwards to slap against the quivering beanbag of doughy fat that was her swelling belly. It bulged out in front of her, pouring over her thick thighs and nudging against the ground as she struggled desperately to raise her weight enough to beat on the glass once again.

“We can’t open the chamber until the gas is purged,” she heard someone snap, “It’ll contaminate this room as well!”
Blurrily through the glass she saw Dr. Mitchell wrestling with another woman, but then her attention was torn away as she felt her sweatpants began to rip, the seat bursting apart as her huge buttocks forced them beyond their breaking point. A second later the legs began to tear as well, first her left thigh, then her right splitting the legs open like plump sausages escaping their casings. Her underwear was long since ruined, now little more than white scraps of fabric around the base of the chamber, but she couldn’t worry about that for long as a second later she felt first one hip then the other come into contact with the walls of the chamber – and still her gain didn’t slow. She struggled for a moment, trying to move into another position, but the sheer bulk of her body was too much, too heavy. She squirmed, eyes widening in ever-increasing panic as her flab began to entirely fill the hypobaric chamber, nude body bulging against the glass, against itself, against everything. Wriggling, she tried to get a little more room, and succeeded only in getting one hand free, slipping it out from beneath the bulk of her own side-flab to slap weakly again against the glass as the pressure once again began to mount, her bulging breasts, belly and rump completely filling the chamber and began, inevitably, to crush her. One of her breasts was pressed up against her face, threatening to smother her with its weight, even as she began to struggle to breath from the sheer pressure inside the chamber.

And then the chamber burst open, and Mina felt folds of her flabby naked, body slump out into the cold air as it depressurised. Staring up with wide eyes, barely able to see beyond her own body, she could just make out the form of Dr Mitchell stumbling back from the emergency release by the chamber, spluttering and coughing on the heavy vanilla air as the Halon C gas burst out into the room, sweeping over the scientists and into the rest of the facility.
Mina could feel her own gain slowing now as the gas dispersed. The scientists were wheezing, fumbling with their clothes as the Halon C began to take effect on their bodies as well; the gas was now too dispersed to do to them what it had done to Mina, but they’d gain perhaps a hundred pounds each nonetheless.

Not that that was any comfort to Mina herself. Gone was the slight research assistant that had stepped into the chamber not even twenty minutes ago; now in her place was this mass of pale fat, the naked immensity of her huge, sagging body half-in, half-spilling out of the hypobaric chamber as the scientists arrayed around her squealed and burst from their clothes.