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You Don't Know What Thirst Is

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Tony ran his hand over the surface of the armour. He should be suiting up. Greg's stupid twenty minutes would be up soon, and they needed to go after Cap, find Anthony, and get Tony's tech back. He sighed. Greg was never going to let him live this down.

There was a crash from behind him, and Tony spun, jerking back and holding up his arm over his face on instinct. When he lowered it, the door was six feet away from the frame, twisted into nothing more than a broken piece of metal. And in the doorway, stood a shape.

"Cap?" Tony shuffled backwards. He didn't have time to get in the suit, but if he could get to the computer he could power up the weapons and operate them remotely. "Cap? Steve? You okay, buddy?"

Steve shifted in the shadows, but still didn't step close enough for Tony to see his face. He braced one hand on the doorframe. His fingers gripped the metal hard enough to bend it, going white with the effort. Or maybe they had been white already. They caught the light, and Tony could see blood dripping from them. He wondered if it was Steve's.

"...Tony…" Steve's voice was barely more than a ragged gasp. He took a staggering step forward, and Tony jerked back again. Steve should be attacking him, ripping his throat out, right now.

"Steve? Are you okay?" He, quite obviously, wasn't, but he wasn't what Tony had been told to expect either. And why was he here?

"Tony… I need help," Steve rasped. He took another step, finally moving out of the doorframe and into the light. His hand slipped from the metal and fell limply to his side, and he wobbled where he stood. His was deathly pale, his skin waxy and bloodless, and he was sweating, forehead dripping. A rusty trail of red marred his chin and his uniform collar, and he panted heavily, revealing two gleaming, razor-sharp fangs. He looked like he was exhausted merely by existing.

"I can see that," Tony said carefully, shifting closer to the computer with every breath. "I don't have a cure, Steve. Sorry. I'm trying, but we're still a ways out from perfecting it."

"I need…" Steve stumbled forward again. "Help me. Please." He took one last step, and his legs gave out. He fell to his knees, chin tipped down, chest heaving. His whole body trembled.

Tony considered the possibility that it was all a trick, trying to lure Tony closer so Steve could murder him. But he hadn't killed Blade, in fact, as far as they knew, he hadn't killed anyone yet. And that meant he probably hadn't fed either. Tony's vampire knowledge wasn't as in-depth as it could be, but he knew their basic needs, and Steve was denying himself the most important one.

"Steve, have you had any blood?"

Steve's jaw twitched, but he shook his head.

"You're starving."

Steve didn't move.

Tony looked from the crumpled form by the door over to the computer on the other side of the room. He could get there easily now. Steve was weak and slow; even if he was playing a game, he couldn't fake the sheen of sweat or the way his muscles twitched and shivered. Tony could get to the computer, he could turn on the armour's weapons, and he could blast Steve back into the hallway.

He took a step towards Steve. "Steve, I'm coming closer. But I'm kinda freaked out right now, so please don't make any sudden moves, alright?”

Steve nodded very slowly.

"Thanks." Tony shifted closer, one step at a time. Why had Steve come to him? He should be mad with bloodlust by now. Every other person infected with Virus X had been as soon as they'd awoken. Maybe Fury was right, maybe the serum was fighting it. Tony slipped down to his knees in front of Steve. Steve didn't move. "Are you fighting it off? I bet you are. Damn that's sexy, darling. Look at you. You're probably the key to the cure too." Tony moved his hand towards Steve very slowly, telegraphing his movements. Steve didn't flinch when Tony's fingers landed on the back of his neck

He was cold and clammy, and when Tony found his pulse point it was hollow and thready, barely there under Tony's touch. Steve was going to die of malnutrition before the serum had a chance to fight off the infection. Tony curled his hand around Steve's jaw, and, seemingly without intending to, Steve turned his face sharply to nuzzle against the inside of Tony's wrist. Steve breathed in deeply, and Tony could feel it deep in his gut.

"You need blood, Steve."

"No…" It was a weak protest when he was currently burying his nose in Tony's skin.

"You'll die…" Tony looked around the room. There was nothing sharp, no cups, mugs, or beakers to drink out of. They were going to have to do this the old-fashioned way. "Come on, darling." Tony hooked the back of Steve's neck again and tugged him closer. As infatuated as Steve seemed to be with Tony's wrist, an injury there would make it hard to control the suit, so he had a different target in mind.

Steve protested weakly as Tony drew him in, his other hand joining the first as he pulled Steve towards him. "I'll turn you, Tony, no," Steve placed both hands on Tony's knees and tried to shove him back, kitten-weak.

"You won't infect me unless you drink enough to kill me, Steve. You won't do that, right? You won't take too much?" Tony lifted Steve's chin and met his eyes. His fangs glinted in the light. His focus was glassy and wavering, but he managed to meet Tony's gaze through sheer force of will. "Steve, I trust you."

Steve whined, soft and low, and he gave into Tony's grip. Tony furrowed his fingers up through Steve's hair, held it fast, then shoved Steve's face into his neck. There was a thin heartbeat of stillness while Steve sucked in a hard breath through his nose, and then Tony's neck exploded with pain. Two fangs pierced his skin roughly, and Steve's lips closed around Tony's skin, forming a seal. He sucked hard, but the blood hadn't started flowing yet, and Tony could feel a bruise forming, his skin prickling.

The suction spun Tony's head with arousal. He'd always liked getting a little rough in bed, but this was something else. He clawed at the back of Steve's head unable to stop his hands from panicking even though he'd asked for this, known what was coming. His heart rate skyrocketed when his grasping fingers failed to dislodge Steve in the slightest. He was completely at Steve's mercy now.

Steve sucked harder, and the blood finally broke the surface around his digging fangs and started spilling in his mouth. Tony gasped, breath evacuated from his lungs as Steve drew the blood out of his veins. A jolt of arousal shot south, and every ounce of blood that wasn't rushing towards Steve's lips starting rushing to Tony's cock instead. He coughed, his hands scrambling against Steve's shoulders again but this time in a desperate bid for a handhold.

It didn't work; he tipped over backwards, unable to support his own weight anymore, and Steve fell on top of him, fangs still buried deep in his neck, hot blood spilling out of his mouth and dripping down Tony's skin, sliding under the collar of his shirt. Steve's hand snapped up between the back of Tony's head and the floor as he fell, even as he growled and sucked harder. Tony squeezed his eyes shut and went limp in Steve's hold. Steve's hips settled between Tony's spread legs and the heat and pressure against Tony's now achingly hard cock sent another wave of heady arousal rushing through him.

He wondered if Steve could feel how turned on he was, if he could taste it buzzing in his blood. Steve used the hold on Tony's head to tip it to the side and give him better access. He slurped and sucked obscenely, filling the room with the noises of his indecent meal. Tony started to feel the loss of blood, his head spinning. But Steve would stop.


Even that thought sent a shudder of electricity up Tony's spine, and he rutted up against Steve's hip, groaning when he managed to get rough friction against his cock. Steve's arms clenched around Tony at the noise, and he rumbled back, and fuck if that wasn't the hottest thing Tony had ever heard.

And he'd thought about this, of course he had. Well, not exactly this, of course. In his fantasies, Cap's teeth were blunt against his neck and it wasn't a matter of life or death, he wasn't slowly spinning towards unconsciousness as Steve sucked him dry.

Well. There was frequently sucking involved, actually.

Steve shifted again, and his teeth bit painfully into Tony's skin, forcing his hips up to grind against Steve again. Steve didn't seem to need air, or if he did, the blood was more important. He didn't pause, or gasp, or break away, even for a second.

"Fuck," Tony breathed. He was actually getting close. As long as Steve left enough blood in him to power his boner - fuck his brain, it could get in line - he was going to blow. He was rutting up shamelessly now, grinding on Steve's hip. "Fuck, Steve, I'm gonna - please don't drain me dry -" he cut off into a moan as Steve wrapped his arms around him. He felt warm and solid and strong above Tony now, the blood flushing through him and giving him back his strength.

The world spun around Tony, and he held on for dear life. This was it, he was dying. His heart stuttered in his chest.

Then the spinning stopped.

He wasn't dying. He also wasn't on his back anymore, he was standing - well, sort of, Steve was taking all his weight - pressed flat against the wall, with Steve still wrapped around him. The sudden move was too much for his already dizzy head, and he took a moment to hold on tight and breathe through rising nausea. When it settled, though, arousal was ready to flood back in and take its place. Steve's arms settled lower, his chest keeping Tony pinned to the wall while one arm snaked around his waist and the other hooked his thigh, fingers digging in just below the curve of his ass.

It was an invitation, and Tony took it. He bucked up against the hard, smooth planes of Steve's incredible body, eyes shut again, the back of his head pressed against the wall. Steve slipped his fangs free, and Tony let out a shuddering gasp of relief and disappointment. But, even though he was sated, Steve didn't step away. He licked over the wounds he'd made, every swipe of his wet tongue making Tony shiver. He tugged on Tony's thigh, lifting it up over his hip, and ground into him. Tony pressed back, completely lost to pleasure and desperation and heart-pounding terror.

Steve sucked gently at Tony's neck, just enough to raise more bruises and keep the puncture wounds from scabbing over completely. Tony could feel the slow trickle of blood still leaking free, but Steve caught every drop, tongue dipping beneath Tony's collar and darting up to taste behind his ear.

Tony thrust forward ruthlessly now, hands fisted in Steve's copper-stained uniform, breath coming in sharp, ineffective pants. He felt oxygen-less and wrung out, unsure if he was about to come harder than he ever had in his life or pass out. When he did come, he wasn't entirely sure it wasn't both. He cried out, holding Steve's firm body against him, and his head spun around in wild circles. He shot hot and hard in his pants like a fucking teenager, without a breath of a touch on his skin except where Steve's hands held him fast and his mouth teased and tasted.

As Tony came down, he lost all strength, his weary muscles finally giving out until he was a limp weight against Steve's chest. Steve lowered him gently to the floor then pulled back. Tony slumped back against the wall. Through a great concentration of effort, he was able to focus his gaze on Steve.

Steve was a mess of blood, smeared over his mouth and covering the front of his uniform. Tony didn't know how much was his, but it looked like a lot. Steve's fangs caught the light again, and Tony tried to reach for them. He wanted to catch a tip with his thumb and see how sharp it was.

But Steve jerked back, his eyes flashing red for a moment. His fingers came up and circled Tony's wrist then guided it back to his own lap. Steve lifted Tony's chin gently and frowned at him. He looked like he was about to say something, but a loud explosion from outside the Triskelion snapped his attention away.

A low growl rumbled in his chest, and he pushed to his feet. There was a moment, a clear definable moment, where Steve visibly decided not to kill Tony, and Tony realized with gut-twisting horror that it meant that up until that moment, he'd been undecided.

He turned and swept out, disappearing back to the shadows.

Tony blinked after him. Shit. He needed a cookie, or some Gatorade. Or a transfusion.

And new pants.

He sat for a long time, just breathing, just listening to his heartbeat. He sat until he heard footsteps coming down the hall. Heavy, familiar, metallic footsteps. He tried to push himself to his feet, but it wouldn't be enough. He was too weak. He would fall.


Steve sweated in the hot desert sun, surrounded by the ash and dust of the expired vampires. He'd done it. He'd found a way to stop them, to save everyone who wasn't already infected. He turned his hands over in the sunlight, looking at the light glint off his palms. He ran his tongue over his smooth blunt teeth. And he was fine, recovered. The serum had saved him. The serum and -

"Attention. This is Gregory Stark," Greg's voice broke through the celebrations. "I'm still underground with one of the clean-up teams, and we've come across something significant."

"Captain America here, Doctor. Define 'significant.'"

"I think my brother might have suffered a fatality," Greg said calmly. Far too calmly.

Steve's heart stuttered. "What? Tony?" Steve resisted the urge to add, but I left him alive.

"Yes. He was attacked. By Stick and the kid. He didn't make it."

Greg's cool detached tone had Steve's blood boiling. He lifted the hammer and smashed it down again, bringing the Triskelion back onto its foundation in New York. It was a long, stumbly trip down the stairs to the labs and the room where Tony stored his suits.

Steve pushed past the SHIELD agents who filled the corridor, gawking and gaping. Greg was towards the centre of the crowd, but Steve ignored him, he kept pushing on, he knew where Tony would be.

And so he was, slumped against the wall where Steve had left him, dried blood caked over his shoulder and neck. His shirt was gone, ripped off his body by the monsters who had shredded his skin.

It was Steve's fault. He'd sucked Tony nearly dry, left him weak and helpless. He'd followed his vampire instincts and fled, protecting himself, and leaving the man who had saved his life to die. "Get out," Steve growled, fists clenched at his sides. There was a listless shuffle around him but no one moved to leave the room. "Get OUT!" He rounded on Greg, flashing teeth that were no longer sharpened, but could still express how much of a threat he could be if angered. Greg took a stumbled step backwards then shoved out of the room, and the agents followed after, eyes lowered to the floor, avoiding Steve's fierce gaze.

When they were gone, Steve sunk to the floor in front of Tony. He landed his hand on Tony's ankle; it was cold, still - dead. There were other bodies in the room, but Steve didn't pay them any notice. Guilt writhed in his stomach like a venomous snake, biting and hissing, and he wondered for a moment if he was going to throw up. He'd lost teammates before, sometimes it seemed like that was all he was good for, but this was different. He'd done this. Sure, he'd left Tony's heart beating - barely - but he might as well have dealt the killing blow.

Steve rose up slightly, ready to turn and leave the room, call the agents back in to clean up. There would be things to do, people to talk to. But as he shifted, the world suddenly spun and twisted and all the air punched out of his lungs. Steve gasped and flailed, twisting in the iron grip pinning him to the floor.

"Tony?" Steve managed to shift around and get Tony's arms in his grip, holding him back as he snarled and snapped. His eyes were open but red and hazy, his skin cold. He howled with rage and hunger then lunged again, spraying spit and sweat in Steve's eyes. He was strong but unfocused, his need for blood overcoming everything else. Steve knew the feeling.

Tony was alive, or at least not dead, and Steve was going to have to kill him again. He wrestled Tony back, cursing when Tony used the advantage of his position and pressed down towards his neck. When it became clear that they were dead-locked, Tony's vampire strength giving him the edge up on Captain America that human Tony didn't have, Tony switched tactics, going for the closest blood source he could reach. He twisted to the side and buried his fangs in Steve's forearm.

Steve cried out and swung as hard as he could, using Tony's off-balance position to send him flying back across the room. He scrambled to his feet and squared up. "Tony, I don't want to kill you, please."

Tony crouched a few feet away, shaking. He blinked hard and the red cleared from his eyes for a moment before flickering back. He shook his head and when he looked up again, the red was still there, but dimmed. "Steve?"

"Tony…?" Steve didn't relax. Tony didn't have super-immunity to dull the effect of the virus; he should be going wild right now.

"Fuck, I'm - ugh -" Tony scraped his hands over his face, and Steve could see they were shaking.

"Tony?" he tried again, unable to resist shifting a little closer this time, trying to get a look at Tony's face. He was pale and sweating, but not as pale as the vampires they'd just fought, not as pale as Steve assumed he himself had been only hours earlier. There was the faintest hint of pink and yellow under the cool, blue-tinged pallor of his near-dead skin, and that little glow was enough to give Steve hope. "Are you fighting it?" he asked.

"I -" Tony looked at his own hands. "Maybe? I still feel like me. Except... there's this terrible hunger under it all. I -" he looked up at Steve, wide-eyed "- I really want to bite you."

"You need blood." Steve scooted closer still.

"You need to kill me," Tony replied sharply.

"No! Not if you're fighting it. Tony you - you could -"

"I could what? Turn into a violent, raging maniac at any moment? Turn into Anthony? I don't fucking think so. Don't let me go down like that, Steve. Please?"

It was the please that snapped Steve's heart in two. He shuffled up in front of Tony and crouched down, hooking one knuckle under Tony's chin to tip his face up into the light. His eyes were tinged red, but not the wild way the other vampires' had been, and his skin wasn't ice cold. It was cool, but it wasn't dead. "You're still alive…" Steve murmured.

"I don't feel alive," Tony choked out. He slipped one hand over Steve's knee and gripped hard, hard enough to puncture the skin of a non-supersoldier.

But Steve could feel life under his fingertips, and he took Tony's other hand and guided it to his own neck, holding his fingers there until Tony's eyes went wide with realization at the thin but steady thumping he felt there. "I don't get it. I died. I know I died. The vampirism wouldn't have gotten me if I hadn't died. Stick - they - I died."

Steve grasped around for an explanation. "The serum -?" he offered.

Tony's mouth opened then closed, then opened again. His fangs hung down between his other teeth, sharp and thirsty-looking. "Maybe… maybe the strain you infected me with was altered by its time in your body. Maybe this is a weakened strain, a different strain. Maybe…"

"Maybe you can fight it," Steve finished for him. "Maybe you don't have to be a monster."

"I feel like a monster."

"You're not acting like one," Steve pointed out.

Tony's eyes raked up from the star in the centre of Steve's chest to meet his eyes. They burned with need. "I want to act like one…" he growled.

"But you're holding back. Come on, Tony. I believe in you."

Tony swallowed hard - Steve could see his throat bob and his jaw clench - then let out a tense sigh. "Promise you'll kill me the second I try and hurt someone."

There was no room for argument. Steve knew Tony wouldn't accept any answer but yes, and Steve wouldn't offer anything else. This was Steve's fault, and he wouldn't let Tony add any more bodies to the pile. "Of course."

SIlence fell.

"Tony... I'm so sorry -"

"Don't." Tony held up a shaking hand. "You saved my life."

Steve gaped. "I killed you." His eyes prickled with a mix of frustration and pain. "This is my fault."

"They would have killed me anyway. There's no way I could have made it into the suit in time. If you hadn't bitten me, infected me, I would be dead for good. Even if I can't fix this, at least I have a chance to say good-"

"Don't." Steve cut Tony off this time. "Just. Don't. Okay?"

Tony nodded sharply.

"Now, you have to feed." Steve started rolling up his sleeve around his already bleeding wrist, but Tony's hand darted out to stop it.

"What the fuck, Steve?"

"What do you mean, 'what the fuck?' You don't have to worry about taking too much - if you kill me by accident, I'll fight off the infection and be alright, just like I did last time. You fed me, now I feed you, it's only fair."

"You might - ah - remember, that was hardly a hardship for me, darling." If Tony could blush right now, Steve imagined he would be.

Steve met his eye and took a steadying breath. He'd been very pointedly not thinking about that, so of course Tony would bring it up. "Who says it's going to be for me?"

Tony's eyes widened again, then he nodded slowly. "Okay… thank you."

"I'd do it even if you hadn't done it for me," Steve hastened to add, realizing how it might have sounded.

Tony nodded again. His voice softened. "I know." He let go of Steve's hand and let him roll up his sleeve all the way, then eased him across the floor until his back was pressed against the wall but he was still sitting. Tony curled up between his legs, and Steve rested his wrist on his bent knee. Tony took the proffered arm in both hands.

Steve held his breath while Tony bent down, scenting the blood under his skin. Steve could remember how it had smelled: sweet, decadent, a little spicy. His mouth watered at the memory even though the thought of having it filled with blood now was repugnant to him. It was the thought of how it had felt then that was warming him from the inside.

And to do this with Tony, to show that level of trust, it was exhilarating somehow. Steve imagined that Tony had shared this kind of trust with lots of people. He seemed like the kind of person who liked to slip a bit of adventure, a bit of danger, into his bed - especially considering the kinds of partners he seemed to gravitate towards. But this was new for Steve, and he was glad he was sharing it with Tony. There was a lot he wanted to share with Tony, if Tony would let him.

Tony scented him again, then licked a stripe over Steve's wrist, just below where his watch band would lie. Steve tensed, and Tony bit down.

It hurt. It wasn't like Steve was expecting it not to hurt, but it really hurt, and he shoved the knuckles of his other hand between his teeth to stop himself from crying out. The last thing he wanted was some SHIELD idiot running in and shooting them both out of fear. If only he hadn't knocked the door off its hinges when he first came in here, then he could have locked them safely in here alone.

After a moment, the initial pain faded, leaving in its wake a low, throbbing sort of ache that ran the length of his arm. Then Tony started to suck, and it shifted dramatically towards something else.

Tony had gotten off on Steve biting him, he knew that, he remembered the way Tony's body had felt against his, hot and hard, and he remembered the full-body shudder of Tony coming, his little cry, the way he went limp in Steve's arms. At the time, Steve's infected body wouldn't let him get aroused in return, the blood no longer flowing there, and he'd been so occupied with his meal that it didn't matter anyway. Getting Tony off had been a way to keep him happy while Steve drained him.

But now he had the combined memory of Tony rubbing off on him while his mouth filled with sweet, thick blood, and now, he was in a body that could actually respond to the idea, plus the physical sensation of Tony, clamped to his wrist, sucking against his skin. It was overwhelming.

Tony had given up all control as soon as the blood hit his lips, and he was drawing the nourishing fluid out of Steve's veins with ferocity now, throat rumbling, teeth rocking in and out of the puncture wounds, keeping the blood flowing. It was heady and horrifying, and with each steady thump of Steve's heart, he could feel himself getting harder. He understood now, why it had done so much for Tony before. He thought it was just the pain, or the lack of control, but it was more than that. It was raw and physical and bound them together, inextricable, just like sex would. And Steve had never had sex like this.

"Tony," fell from his lips before he could stop it, and he could tell his voice was rough and breathy.

Tony's eyes snapped open and met Steve's, glinting with something new now. He didn't completely release his hold on Steve's arm, but one of his hands slipped loose and slid down over Steve's thigh. When Steve arched - almost unconsciously - towards the touch, Tony's hand stroked across his now-tented pants, fingers digging in a little so Steve felt the pressure.

Steve shifted and groaned in a way he hoped was encouraging, and sure enough, though he never slacked his furious sucking on Steve's wrist, Tony responded by popping the button on Steve's uniform pants. It took some awkward rearranging - to get Steve's belt out of the way, the zipper down - but finally, finally Tony worked Steve's cock free of his boxers and stroked his hand from base to tip in a firm grip.

"Ah, fuck," Steve cried out, thrusting up into Tony's hold. Tony's hand was cool, but Steve was sweating now and it felt nice, almost foreign since Steve's hand on himself was usually overheated. Tony moaned, pumping Steve faster now, and Steve wasn't sure if it was in appreciation of Steve's reaction, or the blood spilling onto his tongue.

Steve was going to finish embarrassingly fast at this point, but he honestly didn't care. His body was singing with chemicals - adrenaline and endorphins rushing through him - and it was the closest to being numbed by the sweet relief of pain-killing drugs that he'd had since the process that had turned him into Captain America.

He felt like he was floating, nearly separated from his body, a wave on its peak right before it crashed down into the surf with a rush. He held his breath, tensed every muscle. Then Tony sucked harder, fangs biting in deeper, and stroked down firmly, and Steve did break.

He spilled over Tony's cool, pale fist, hands twisting in the fabric of his pants so he wouldn't snap them up and break Tony's wrist, or rip out his hair. His breath came back in a wild gasp, and he shuddered from head to toe.

Time passed in a haze - it could have been minutes or hours before Tony slipped his fangs free and licked Steve's wounds closed. Spit and blood dripped down Steve's forearm and onto his pants and the floor. His come had splashed down onto his boxers and the fly of his pants, though most of it still covered Tony's hand. Tony seemed to notice this at the same time, and he brought his filthy hand to his mouth and licked that clean too, while Steve watched, mesmerized.

Tony slumped across Steve's lap, his legs twisted around through Steve's, head pillowed on Steve's thigh. He gazed up at the ceiling, chest heaving. "Wow."

"Mmm," was all Steve could manage in reply. He flicked his eyes down to match Tony's red-tinged gaze, and they stayed that way for a moment, silence settling heavily over the room.

"I'll find a cure," Tony finally said softly, and Steve wasn't sure if he was trying to convince Steve, or himself.

Boldly, Steve reached out and wound his fingers through Tony's, resting their joined hands across Tony's stomach. "I know you will."