The only thing that could be even slightly made out from the cloudy room on the other side of the glass was a huge figure, standing almost ten feet tall, its body heaving with heavy breathing.
"What the fuck is that?" Tony shouted.
"How should I know?" Steve asked, running out into the corridor to look through the bigger glass pane. It didn't help; the cloud was too thick.
There was nothing. Nothing but the big shape, towering ominously over what seemed like a small lab now.
Tony ran out with Steve, rammed his key into the lock, and twisted the door open.
The gas that streamed out was just cooled oxygen, so that was a plus. No noxious gasses to knock out Bruce. Both of them cautiously wandered into the room, keeping their eyes on the massive, heaving shape in the middle of the room, completely silent. Steve almost tripped over a random object on the ground: it was Bruce's pair of wire-framed glasses, a crack running through both of the lenses, the frame bent out of proportion.
The gas had hardly gone out of the room by the time the door clicked shut and the figure moved, disturbed by the noise. And it headed right towards Steve.
"Tony! Tony, it looks like-" Steve started to say, but the thing, a green, almost-human monster from what he could tell, sent him sailing across the room. He landed right by the lab table, which had also been sent across the room. Steve guessed that's what made the thud.
He grabbed the table, and, with the advantage of the activated super soldier serum coursing through his veins, turned the legs in, making it a shield.
"Tony!" He shouted again, still not completely able to see him. "Tony!"
"I'm here," Tony responded. Steve couldn't tell where it was coming from, but it was something. With the shield always facing the monster, Steve ran for the door, trying to open it.
"Damnit! I almost forgot that the door locks on the inside, too. Tony! Come over here, with your key!"
But instead of hearing Tony's voice, Steve heard what could be only described as a subhuman roar. Tony landed at Steve's feet.
"Steve, it's Bruce..." Tony barely said, the air knocked out of him.
"You found him?" Steve asked excitedly.
"No, you idiot. He is the thing! That horrifying green thing... it looks like him, sort of."
"You do realise this entire room is a vacuum? We're only going to get rid of this gas if we open the door," Steve said, trying to be tactical and ignoring Tony's insane rant. "Where's your key? If we clear out the room, we can get a better look at whatever this thing is."
Tony tried to fumble around in his pocket with what energy he had left from being launched around the room.
"Sometimes, I forget that I'm the only super soldier around," Steve mumbled to himself, and forced his hand into Tony's pocket. "You gotta realise, Stark: We're in a large lab room, but the thing, whatever it is, that we're dealing with here is big, too. We don't exactly have a lot of wiggle room." He pulled out the key, shoved it into the lock, and pried the door open with Tony.
"Stay put. Keep this door open. I need the visibility to take down whatever this thing is."
"Yeah, Cap," Tony breathed, "I got it. But you aren't hearing me: I'm almost positive that it's Bruce!"
"I think you hit your head harder than you think you did," Steve let out a small, nervous laugh, and headed back into the thinning cloud.
Tony heard the same roar that preceded his launching across the room, and heard a bang similar to that of metal on metal. Steve was launched backwards in his defensive position. The only thing that was different was a huge fist imprint on the little lab table-shield that was wrapped around his right arm.
"Right then," Steve gasped for air. "Let's let the rest of the cloud go away before we try to take this guy down again."
"Yeah," Tony replied breathlessly, making room for Steve next to him by the door, "I'm pretty sure we can rule 'guy' out as a possible explanation, don't you think?"
Steve put his shield down as a small fortress in front of him and Tony, resting his head on Tony's shoulder. "Well, I can give him one thing."
"And what would that be, Captain?" Stark asked, resting his head on top of Steve's.
"He can pack one hell of a punch." Steve glanced at the punched in table, and let out a nervous laugh. Tony kept quiet.
"What if I'm wrong, and Bruce really is gone?" Tony asked, his voice shaking. Steve could see the tears in Tony's eyes that he was trying to hold back, the lump in his throat that was preventing him from sobbing
"What if you're right, and Bruce is the big green thing we saw, that threw you across the room and-" Steve cut off suddenly. "The room is basically clear," he whispered, "and look."
The beast that they had been fighting sat in the corner directly across from them, wrapped around the original gamma ray mechanism. The beast towered over the lab room, its body filling up the entire corner it was in and then some. Steve's first-look impression was right by two details: it certainly was green, and it was more humanoid than what was expected. Hell, it looked like it was just a large, green bodybuilder wearing shorts.
When it looked up, Tony and Steve gave it direct eye contact, and immediately its breathing quickened, the entire body of the monster tensing up like it was about to attack.
"Hey, Cap, you still think I'm crazy?" Tony asked. "Look. Look at the face, the eyes."
When he did, Steve saw what Tony meant. The face of the beast, though it was much squarer, harsher, and, well, greener, had what looked like the features of Bruce. That was one thing.
But the eyes. They may have been green, and they may have been becoming savage with rage toward the two people he probably didn't want to see right now, but Stark was right. It was Bruce.
Slowly, Steve got to his feet. "...Bruce?"
Tony struggled to his feet shortly after. "Steve, let me. I've known him for so long, we're basically brothers." As they both got up, the door clicked shut, and the rage in the monster's-well, Bruce's-eyes skyrocketed. Nonetheless, Tony kept walking towards it-towards the monster that until moments ago was his best friend.
"Bruce. It's me, Tony. Your buddy since, what, the third grade? Damn, could it really have been that long?" Steve could hear his voice get choked up. It couldn't be easy to see your best friend of over seven years in the form of a giant green rage monster, about to leap on you and attack you.
But, whatever Tony was doing must have been right. Because for just a split second, Steve saw more Bruce than monster in the eyes of the big green hulk.
"Right. Just calm down, and we'll get this entire thing fi-" Mid-sentence, Tony was launched through the air, hitting the glass paneling and falling down in a fetal position, out cold. Steve felt like his heart just dropped down into his stomach after Tony made no movement after his impact with the glass.
"HULK NO CALM DOWN FOR SMALL MAN." Steve could hear a deep, almost human chuckle arise from the chest of the monster.
"Bruce!" Steve shouted, as though scolding a child. He straightened his posture, adjusted the shield on his hand, and began to walk towards the massive green thing. "Tony was trying to help you! You do realise, that-"
"LEAVE. ME. ALONE." The monster growled. Bruce's eyes gleamed with sorrow behind the green, enraged eyes. Only for a second, Steve felt like he should listen to Bruce's monster, but his soldier subconscious decided otherwise.
He held up his mauled shield proudly, marching toward the huge green hulk like he was going to be a hero. He stopped about ten feet away, and proudly declared, "Listen… Hulk, was it? I know Bruce is in there somewhere. So, let him back out. You just smacked your best friend across this entire lab room, and now he's lying over there, completely unconscious. I will avenge him, right now, while you are in this state and Bruce has no power. I-"
The Hulk began to throw a huge, green fist at Steve, but he blocked it with the shield. "I'm sorry," he straightened the shield and brushed some rubble off of his shoulder, "I wasn't done yet."
"HULK DONE LISTENING." And he smacked Steve across the room to the same spot that Tony landed. Steve's body of steel impacted and cracked the glass in the same spot, and he landed chest-down with his arm sprawled across Tony's chest.
Before completely fading out, Steve saw the Hulk sit back down in his corner, the breathing slowing, and his eyes closing gently.
That's the last thing Steve remembered of that night.
