You stood in a dressing gown in front of the chamber door. You pulled the flannel material around yourself a little tighter, you were on first name terms with the men and women around you, some measuring your vital signs, some monitoring the conditions inside the test chamber. On the other side of that airlock was a carefully calibrated environment, as close as possible to the environment where the entity within was found. There were certain peculiarities about its genome that needed to be answered for. That's why you're standing here.

You couldn't get a volunteer for this. You'd seen what this thing did to a rat, no ethics board in the world would let you subject a human to that. Luckily, you had a can-do attitude, a willingness to put your life on the line for science, and, though your colleagues wouldn't hear it from you, a bit of a kink. 

“You sure about this, Doc?” One of the lab techs stood with you by the airlock door was looking at you. You didn't remember his name, he'd transferred from a different department recently. You figured you'd learn it afterwards, no point stressing about it now.

“I'll be fine. If I wasn't going to be fine, I wouldn't be here.” Your words were full of determination, even as other colleagues silently echoed his concerns. Still, nobody wanted to have to scrub the test. The only way you could do this was for one of you to do it. Nobody could do much as ask someone to do this. It's only possible because you said you'd do it, without prompting, without even asking if you were allowed to volunteer. You wrote the experiment, and named yourself explicitly as the testbed. Everyone in here knew the stakes.

As if to illustrate your point, you dropped the dressing gown. The men in the room stiffened up, you imagine in more ways than one. The effects of textiles on it wasn't in the remit of the test, so you were going without. That means not wearing even a single stitch while you were in there. 

“Containment status is green across the board.”

“We've got the baseline of your vitals, ready when you are”

You helped the blushing technician remove EKG probes from your skin, peeling off the gentle adhesive and letting them fall to the floor. They were everywhere, several attached to your breasts, a few on your neck, a few more on your belly and your back. Every inch of you had been logged for a baseline. You'd even had ultrasound scans taken to get imagery of your organs. 

At long last, you were ready. Hair down, tits out, butterflies in your stomach. You nodded at the man at the airlock. He spun the wheel, opening the outer door. You stepped inside. The airlock cycled.

You were inside the rest chamber now. The entity likes it cold, and damp. You shivered, climate control kept the room at a balmy four Celsius at 95% humidity. A slick layer of cold water covered every surface, nothing in here was dry. A pallor of mist hung over the room, you knew the thermal cameras could see you, a beacon of endothermic clarity in a soup of cold vapour. Water clung to you, the mist sticking to your exposed skin. You shivered, the cold cutting into your body, you couldn’t stay long, so you had to make sure you got this right. You stepped forwards.

The environment here was set to mimic a forest in Northern Europe, cold and wet, mosses and lichens covering an uneven floor of limestones and humus. Dull light filtered from above, designed to mimic the sun filtering through a thick, even layer of clouds. The time was set to mid-afternoon, the light levels you’d expect an hour or so before dusk on a winter’s day. You had noticed that as a good medium between being dark enough to encourage activity in the subject, and bright enough for you to not twist an ankle and need rescue. Everything was controlled for. You hadn’t even showered today, just to try and make sure there weren’t any residues clinging to you. One shot meant one shot.

You heard motion nearby, just to your right. You knew what it was, but also knew to keep your cool. It had been fed recently, a sheep carcass stripped to the bone. It even etched the bones. In theory this beastie was a scavenger, the perfect decomposer. Throw in any and all detritus, then simply watch it dissolve. Only problem is, there’s only one of it. You’d never found another, and any cuttings you took to try and grow another never lasted long. 

You mused on these thoughts as you sat down. Hopefully acting unaware would spur it into motion. You looked up at the viewing gantry, a strip of windows in the simulated sky. You held your arms up, fingertips touching, a great halo to indicate OK. You weren’t OK, you were cold, wet, and shivering, but if you let them know they’d turn up the lights and scrub the test. Couldn’t have that.

More movement. Right behind you. It had your scent. Maybe it caught a whiff of you when you signalled up above? Maybe it always knew you were in its domain, it was just waiting to see what you’d do. Either way, you could sense it looming behind you. Until it stopped just looming.

The mass of it shocked you, as did the cold. It flowed around your body, covering your skin. The entity was an organism made of living fluid, your best estimates were that the semi-solid core at the centre was what gave it animation, everything around that was simply an oversized gastric system. Now, closer up than any human had come to it, you felt like you might be right. The core floated in the greenish-half light, you reached out to it, hand passing slowly through the fluidic mass. You cradled the dark splotch in your grasp, feeling the slight warmth of it against your fingers. 

The moment you touched its core, the creature’s demeanour changed. You could feel it. It was moving with purpose now, not just investigating you. The slime crept in through your nose, filling your mouth in an instant as you coughed against it. It flowed into you, reaching your stomach in moments, then kept going. It was advancing from the other side too. You spread your legs.

You’d lie later in your report, tell them you weren’t expecting this, hoping for it. That you hadn’t had recurring dreams about this precise moment since you first took charge of this project. You knew they’d review the footage though, hopefully they’d see your hand stretching for your crotch as a defensive reflex, rather than noticing how instead of trying to cover your folds, you were holding them open wide, inviting the creature in. 

It didn’t take much inviting. It was already finding its way into your body, filling you up. Both your cunt and your ass were full of the slime now, feeling it explore you, sliding through your belly, wriggling upwards, joining in the middle with the tide holding your throat open. It had you threaded like a needle, an unbroken current of ooze passing through the length of your body. 

You felt lightheaded. Was it secreting something? Or was it just the lack of air? You choked on it, and it pushed you upwards, exposing your face to the outside, pulling back just far enough to take a panting few breaths, then sinking you back into the mass. Your hand started to move, rubbing your nub as you felt yourself sinking again, the cool mass enveloping you again. You couldn’t make a noise, your throat full of throbbing slick, but you could feel your filled nethers starting to clench, the foreshocks of your release coming upon you. Every time you twitched down there, a fresh wave of pressure flowed back in, giving you more and more to squeeze against, until your toes curled and your eyes rolled. 

By the time you reached your peak, your ears were ringing, tongue out and eyes crossed, you felt your body convulse, throwing your head backwards as you screamed wordlessly against it. 

It took note. You definitely weren’t food. You felt the core sliding over your body, splitting as it went. One became two, then four, eight, sixteen, doubling every few seconds as they slid their languid way over you. You lost count of how many times they split, before they began crowding over your holes. You felt every one slide in, soft, but still more solid than the slime already filling you. Each one stretched you a little, slipping in down your throat, up your ass, inside your cunt, nestling in, stretching you out to make space. In moments, you crested another peak, then another, the sweat wicking away from your skin into the slippery medium covering you.

Then it left. 

You lay on the ground, slick with moisture, the residue from the entity. Getting to your feet was difficult, every motion squeezed a few nascent cores from you, landing with muffled splats on the manicured vegetation below. You didn’t stop to mourn a few, not when your belly housed so many more. You reached the airlock, turning the wheel to open it, then another to cycle. That same lab technician draped your gown over you, as you clambered into a waiting gurney.