Simple Injection

I was stopped in the dark by two burly men, who, with the help of a large baseball bat, knocked me out. When I woke up, I was tied tightly to a chair, my jacket and pants removed, and gagged with about three different methods. The chair was like a dentist's, and the room was a small, grey thing, with a bright lamp shining down on me. I was in a hospital of some sort, and I immediately began struggling, trying to wrest myself free.
A man in a long coat entered, standing in front of me, and I paused. I could only watch as he smiled, opening up a case where ten different syringes were carefully packed. He looked up, eyebrows raised.
"I suppose you're wondering why you're here." He said. Knowing full well I couldn't respond, he continued the one-sided conversation. "You've made quite a few enemies, Jared. And one has paid me good money to ensure that you won't be getting in her way for a while. So, what I have here are several different serums. None of them will kill you on their own, but if mixed, they could have very... unpleasant reactions. Let's pick one, shall we?" His handed danced over the needles, and he picked up one delicately, examining it. "I think this will do. I am doctor Helinski, by the way."
He strode towards me, the syringe catching the light, and I tried to wriggle free, away from him. He simply laughed and pushed the needle into my exposed arm, grinning as I gasped. He quickly put the needle away, closing up the case and waiting. I stared at him, waiting for... something. He smiled once more, staring at my stomach. I sighed, looking down. It was distended, and growing. I looked back up at him, trying to get across the fact that I was not impressed with his ideas.
My belly shot out quickly, building up pressure as it swelled. I closed my eyes. I could feel it hit my thighs, rounding out some more, and pressing against the sides of the chair. Helinski was giggling to himself, and I opened my eyes, looking down at my stomach. It was huge, straining over the sides of the chair and spilling into my lap. It was also fairly light, but I felt like it was about to explode.
The doctor came forward, poking it, and inspecting me. I tried to squirm away once more as he poked and prodded me from all angles, and I felt increasingly like a test subject and less of a human being.
"Fantastic. Good." He muttered, as he pressed his hand to my belly once more. I grimaced at the pressure, and a malevolent spark appeared in his eyes. He grinned, pressing down on my belly. I managed a groan from behind my gag, but that only spurred him on. My belly began squeaking slightly, and at that point he let up, removing his hand and leaving a handprint on my taut stomach.
"About to burst. Interesting." He said, smiling. He patted my belly gently, and then walked away, taking his case of needles.
"We'll keep you a few weeks, until you deflate fully. We should let you go then." He called tauntingly as the door swung shut behind him. I groaned weakly.
I was not looking forward to this.