Steve looked straight ahead as Stark held the sonic device's barrel directly in front of his face. There was an unmistakable twitch of fear in Tony's stern expression when he fired. An agonizing pain split the back of Steve's neck. The Captain yelled out, screwing his eyes shut just as the pain disappeared. He tried to lift his hand and touch the spot where a spear of fire stabbed through his skin, but he couldn't move. Obviously. Opening his eyes again, he saw Tony watching him intently with his best researcher face on.
Pulse normal, breath slowing. Everything seems fine. Tony chewed the end of his finger nails as he watched the monitors, then Steve, then the monitors again. After a minute, he felt a tide of relief. It was working as planned, and the Captain could still talk. The paralysis began at the base of the neck, clearly the cause of sudden pain above Steve's shoulder blades. Hopefully he'd forgive him. Did sound kind of intense though. The test subject kept asking how he was going, if it was working, how long he had left, if this part should feel right. Tony was happy to report only positively.
The knot of fear disappeared from the engineer's chest and he could observe in peace. Steve looked physically normal; his skin was fine, there wasn't any pain like last time, the paralysis only occurred from his neck down so he could talk, his limbs didn't appear to be losing circulation, and the taut muscles along his torso were rising slowly with each breath. It suddenly dawned on Tony just how vulnerable Steve was. He could reach out and touch him. Run his fingers down his chest. Slide his hand over his thigh and under his- no, God, what was he thinking? He snapped out of it, swallowing nervously when he saw Steve's eyes on him. There was something utterly alluring about Steve Rogers, a super soldier who could easily break his wrist in a second, unable to move. Unable to push Tony away.
The Captain stared up at the blank white ceiling. There was a strange mix of tranquility and fear with not being able to move. He'd been paralyzed once or twice before on SHIELD missions, but not in the same way. After the sudden unbearable strike of pain, it was more than fine. And his injured leg stopped throbbing. The faint beeping of the monitor out of sight reassured him that everything was going as planned. His eyes followed Tony as he watched him closely, pacing between the side of his still body and the monitor screen. Steve felt safer knowing that someone he trusted was conducting the test and making sure he was okay. Of course, Tony would be more concerned with actually experimenting the paralysis device, but Rogers knew the engineer was watching for any sign of trouble on the Captain's behalf.
Tony was running his eyes up and down Steve when he heard the monitor grow louder. Turning to the screen, he noticed the heart rate was normal, but Steve's breathing was becoming inconsistent. Reassuring himself that it was just the paralysis wearing off, he looked back down at the Captain. He was wrong. Steve's mouth was open, his neck straining to move. Short gasps escaped from his throat. If his chest could move, it would be heaving.
But he wasn't the only one panicking; Stark reached for the waiting paralysis device, quickly switching to the setting that should revert the temporary damage to the spinal cord. He didn't hesitate and fired it in front of Steve's quickly reddening face. All he did was lurch his head up and cry out in agony with what minimal breath he had left.
The Captain was panicking. Nothing else. He'd had non-stop troubles with his respiratory system when he was younger, but never like this. He knew Tony would have a plan. He couldn't breathe. And as much as he told the muscles in his arms to move, they wouldn't budge. Stark had fired the paralysis device at him again. Nails of ice had driven into his neck. A wave of chilling pins and needles ran painfully down his entire body. He still couldn't move. And he still couldn't breathe.
Stark tried to calm down and think. He had thrown together a mental plan beforehand if something like this happened. But his mind was failing on him. Rogers was regaining control of his limbs but not his lungs. A sudden thought flashed into Tony's mind, but he quickly dismissed it. But seeing Steve helpless under Tony's own selfish needs brought it back. The engineer drew and held his breath, then pinched the Captain's nose and planted his open mouth firmly down on the other man's.
Steve gasped, filling his lungs with much needed air when Tony withdrew. His legs shot to life and he sat up, his arms clutching his stomach as he hyperventilated. Tony sighed in relief, his hands shaking from the fear. Steve tore the sensors from his chest and the frantic beeping of the monitor cut out. A pain shot through his shin, his lungs, his neck, his spine, and he fell back again, lying and panting on his back.
"I'm- I guess-" Tony tried to place his words, "that didn't go as smoothly as anticipated. I mean, of course that was meant to happen. Just finding variables."
Steve cracked a crooked smile, his breathing quickly coming back to normal. After being on the edge of passing out, the Captain sure recovered quickly. Tony truly admired the man's stamina. Sure, he himself was physically fit, but compared to Captain America? Fuck, that guy was a superhero for a reason. How long could he last in- no, stop thinking like that. Even for him, going after Captain America would be wrong. He'd teased and poked at the other man countless times, but none of it was serious. And even if he wanted to change his motives and really act on the advances, now was not the time. Just moments earlier, Steve was dying because of him. And then he was improvising, and pressing their mouths together, and imagining those lips pressed to his-
"Mr Stark?" Steve's voice cut Tony out of his daydream. Making eye contact with the Captain was near impossible.
Steve continued. "Maybe that didn't go incredibly smooth. But you also, from what I can tell, just saved my life. Again. And don't say any of this was your fault, either, because I agreed on it. I'll take responsibility."
Tony was slightly taken back with how sympathetic the Captain was being. He had enough reason to be fuming, yelling insults at Tony and how reckless he was, and storming out of the lab and ignoring him for the rest of the week. The engineer had no idea what to say back; he wasn't even sure if his voice would work from how captivated he was. Instead of replying sincerely, or snapping back with a sarcastic comment, he threw the sonic device into the case and walked quickly out of the lab without another word.
