There's no such thing as monsters.

It's a child's mantra, whispered at night to keep away the evil lurking under the bed, the demons hiding in the closet.

But Natasha had learned, far too soon, all the reasons in life to be afraid. And she'd conquered them, one by one, until there was nothing left to haunt her dreams, nothing lurking in the dark corners of her mind but herself, and the things she'd done.

Natasha knows that monsters exist, because she's been one.

But now, with huge green fingers wrapped around her chest, tightening every time she breathes out, she's one monster in the hands of another.

x-X-x

It doesn't sting at first – Natasha is very hard to offend – but eventually she can't ignore it anymore, the way the Hulk favors the others in his own way; teaming up with Thor in fights, protecting Tony's back, pausing to listen to orders from Cap and actually managing to follow them some of the time. Even Clint's gotten the occasional lift to a higher perch from the big guy.

But not her; never her. The best Natasha can hope for in a fight is to be ignored completely by him, and mostly that's okay with her. Or it would be if it didn't feel like some kind of judgment, like a trial she's failed to qualify for, a limit just out of her reach. Of course, she phrases it differently in her head when she's planning what to say to Bruce, making it about acceptance and trust and teamwork, ruthlessly ignoring the part of herself that knows it's something deeper than that, something all tangled up in fear.

Somehow it all goes out the window anyhow the moment she sits down across from him, across from his steaming cup of tea and the datapad he's borrowed from Tony.

"Why doesn't he like me?"

Bruce shifts slightly in his chair – if she's nervous around him, it makes it a little better that the feeling is so obviously mutual – and looks up at her. "You're going to need to be more specific than that. If this is about Tony, I think he's gotten over the whole security thing-"

"No," she interrupts (privately she's certain Tony was more amused than anything when she'd managed to disable Jarvis' surveillance in her suite), "not Tony. You. The Other Guy."

"Ah," he says, leaning back and folding his hands around his cup. "You noticed that."

"Yeah."

He glances at her, wary, with that sideways, apologetic look he assumes so often, and she hates it already, knows she'll hate what he's going to say before it even comes out of his mouth.

"You smell like fear," he says simply, and shrugs, as though that could remove the sting from his words. "I don't blame you. But the Other Guy – he doesn't like that so much."

Natasha knows fear well, like an old friend. She's learned to use it, to call upon it, making it one more trick to speed up her heart rate, her breathing, anything to make her seem more believable in a given role.

But this isn't a role, isn't something imagined that she can switch off at will, and suddenly she's finding it hard to breathe, like all the glass walls of Stark's tower are about to crush in on her.

He's stopped watching her, seeming focused on the glowing screen in his hands, but he looks up again when she stands, maybe just a touch too sudden.

"Don't worry," he says, soft and gentle, like a man constantly trying to hold back an avalanche. "I won't tell anyone."

She breathes evenly, in and out, trying to rebalance her skeleton inside her skin, and leaves without another word. Fear, like love, is for children, and Natasha will tolerate neither.

x-X-x

He seeks her out two days later, and finds her curled in a chair reading. He waits for a moment just on the edge of her vision, hesitating, fiddling with his pockets, easy to read as a child's picture book.

She waits until he clears his throat before finally raising her eyes from the page. "Dr. Banner."

"Natasha. I was wondering – if you were thinking of having dinner here, I'd think again. Tony's in the kitchen creating some unholy abomination and-"

"I wasn't," she says. Tony's attempts at cooking always turn out the same – disastrously, with Jarvis threatening to set off the sprinkler system before Tony gives in and orders out for everyone. "I'm not really that hungry."

"Oh," he says, and turns to go before swinging back around. "Cause if you were, I was going to ask if you wanted to go out somewhere. Maybe get a little...exposure therapy, so to speak." He's giving her that apologetic look again, with that little half smile of his added on. She ought to hate it, ought to hate how uncomfortable he still is around people, how awkward and tentative.

Instead, she finds herself smiling back. "I'm not frightened of you, Bruce."

"No," he says, and watches her for a long moment, long enough to make her wonder if she's somehow misread something here. "No, of course not. Forget it."

She lets him get all the way to the door before her curiosity snaps. "Just let me grab some shoes," she calls, and is gratified when he doesn't even look surprised.

x-X-x

He takes her to an Indian place, and though it's a far cry from Calcutta, the close heat and spice in the air are enough to remind her; she wonders if he knows about the weapon holstered at the small of her back, about her earpiece always on, always ready to send out a signal if his eyes show the slightest hint of green.

He must – most people don't forget having a gun pointed in their face – but she wishes he didn't, all the same.

He puts his hands flat on the table and talks calmly of inconsequential things until she forgets to remember.

Eventually, she even remembers how to laugh.

x-X-x

"The city's kinda nice, when you give it the chance to be," he says on their walk home, tipping his head back to look at the sky, as though it's possible to see anything other than the city lights reflected back down on them, the crisscrossing shadows of construction cranes leaving stripes across his face.

"When it's not full of things trying to destroy you? Yeah, puts a whole new spin on the place," she answers, and waits for his soft chuckle beside her.

x-X-x

It isn't until they get back to the Tower to find the others sharing a pot of coffee and discussing former girlfriends (mostly Tony's, of course, and Natasha has no desire whatsoever to discover how they got onto the topic), that it hits her.

She's hopped up onto the counter to sit next to Clint, casually bumping her shoulder against his, waiting for him to nudge her back, let her know everything's okay with him too. And then she watches Bruce.

Watches him slide into a seat at the table and accept a mug from Steve; watches him make a wry observation on Tony's former taste levels and get slapped on the back by Thor in appreciation. Listens as he helps the others draw Clint into the conversation, needling him about SHIELD agents past and present.

Being wrong doesn't sit well with her; it never has. She lets that explain the twist in her gut, the spreading hollow inside that throws her even more off balance as she realizes – it isn't that Bruce is uncomfortable around people. She sips her coffee to hide her face, and grapples with the knowledge that he's just uncomfortable around her.

x-X-x

When she knocks on his door several hours later, her blood is already up; she's angry and she can't pinpoint quite why, which only serves to make her angrier.

That's what she blames for pushing past him as soon as he opens the door, slightly rumpled and squinting.

"Why didn't you tell me you're scared of me?" she demands, diving right in.

"Well, if I would have known it would get you to burst into my room at half past midnight..."

"Don't even start with me, Bruce. This 'exposure therapy' of yours – it wasn't for me at all, was it? It was for you."

"Can't it be good for both of us?" he asks, watching her warily.

"I told you," she hisses, stalking towards him until he's backed up against the wall. "I am not afraid of you." She knows this is stupid, knows this is beyond the point of acceptable levels of risk, but she's getting too tired of it to care, tired of feeling compromised by these people.

"No," he says, and she's so close to him she can watch his throat as he swallows, can feel the heat coming off his skin, inches from hers. "But you should be. You, more than anybody."

He isn't trying to avoid her eyes now; he's looking straight at her, steady and heated and completely in control. "And I'd be an idiot not to be afraid of you, Nat."

When his fingers brush across her wrist, she tenses, and it all flies through her mind in an instant – her throwing him to the ground without a second thought, him turning giant and green and terrifying, and her ending up broken to bits beneath him – before she closes her eyes, and breathes, and feels his hand fold around hers.

x-X-x

"I smell like fear?" she asks later, sitting with her forehead pressed against the cool, tempered glass of his windows, looking out at the city lights clustered below.

"Yours, and his," Bruce answers. He's sitting next to her, close enough to touch; if she angles her head just right she can see both the man and his reflection, like pieces of a whole. "He isn't scared of the others – he isn't scared of much of anything, really. But you, well..." He looks at her, and she turns her head, just enough so she can only see his reflection, before she lets it blur and focuses outside, on the city.

"He thinks I'd kill him." She leaves it as a statement, not a question; she knows it because it's true. It's one of her personal directives – if anyone on the team ever got turned, ever became more of a danger than they could handle, she would take them out, no muss, no fuss. Keeps her safe, keeps her team safe, and removes any burden of guilt for the rest of them.

"That's part of it," Bruce says, sounding serene as ever at the prospect.

He doesn't elaborate, and she refuses to allow herself to ask.

x-X-x

"Maybe I am scared of you," she says, as she's walking through his door. "But not for the reasons you think."

"You might be surprised at what I think, Natasha," is all he offers in return.

There's a promise and a threat and everything she's never wanted in his expression; her mind calculates the risk and uses it to ruthlessly fill the hollow ache in her chest, reminding her of one essential fact.

Nobody loves a monster.

x-X-x

Three nights later, Clint decides they need to put the bar to use, and Tony's only too happy to oblige, passing around obscenely expensive bottles of whiskey and wine and vodka and mixing up drinks that should probably be qualified as toxic.

Natasha makes her own drinks, and lets her eyes wander over salt and pepper curls and a wry grin; lets her mind wander and calculate and bargain, just for this one night.

Things end, predictably, with Clint and Tony teaming up to slur the most vulgar limericks they can think of at Thor, who responds with bellowed Asgardian drinking songs that are even filthier in translation, or so he claims. Cap, who can't get drunk any more than she can, is watching with what she suspects is feigned horror and real amusement, and Bruce...well.

She's surprised that he'd been drinking at all, wondering if the Hulk would consider alcohol a poison in need of eradication, but apparently Bruce knew their limits, sticking to a few glasses of red wine.

"You don't have anything to contribute?" he asks, coming up behind her and leaning forward to be heard over Tony's particularly inventive version of 'There Once Was a Man from Nantucket'. His fingers brush a curl back from her ear almost absently, like it's an old, familiar gesture, and her skin tingles. "No dirty Russian songs?"

"We don't go in for a lot of boasting in Russia," she says, and makes her choice, leaning into him, deliberately letting her eyes drop to his mouth. "We just do."

She can feel Clint's none-too-steady gaze on her back as she leaves the room, but more importantly, she hears: the clink of Bruce's glass being set down, the sound of his footsteps following.

x-X-x

He is, for such a deferential man, a surprisingly bold kisser, and Natasha finds herself on her back in his bed in no time, the fire in her blood having nothing to do with alcohol and everything to do with the way his fingers feel sliding over the bones of her ribcage, the way the hair on his chest tickles against her fingers as she pulls at the buttons of his shirt.

She's never been the type to take it slow; there's something primal in her, something deep down at the core that loves the way he's got one hand tangled in her hair, that pushes her into thrusting her hips up to meet his, that's satisfied by the not-quite-human growl that comes from his throat.

And then there's the part of her that remembers, as she hears fabric rip (her shirt or his, she's not really certain), that she's lying half naked under a man who could turn into a monster at any minute, remembers Bruce's eyes staring out at her for one last moment from a demon's face.

"Nat. Natasha," Bruce says, and she blinks and comes back to herself to find every muscle in her body gone rigid and tight, and Bruce next to her, buttons all undone, propped up on one elbow. "It's okay. We don't have to – I get it."

Her breathing comes under control soon enough, and she wants to laugh at herself, bitterly. For all the times she's thought of this in the last few days, she always assumed it would be Bruce who called a stop to it, Bruce who wouldn't be able to handle the possibility of losing control.

"I understand if you want to go," he says, sitting up. "I won't get angry."

For a moment she's tempted, tempted to run out the door, out of the Tower, and never look back, to go back to an existence where there was no team to worry about, no one she needed to trust, nobody who even wanted to get close enough to see what was behind her eyes.

And then she looks at Bruce, at the defeated slump of his shoulders as he sits there on the edge of the bed, as far from her as he can get without being obvious, and she knows it's too late for that, too late to run and hide.

Moving up slowly behind him, she murmurs, "I don't want to leave," against the back of his neck, and eases his shirt from his shoulders. "Can we just...try lying here for a while?"

"The Black Widow wants to cuddle?" he asks, and his voice is dry, but wary too, and for a second she feels like she can hear the Other Guy's voice as clear as he can, sneering words like pity and pathetic. Still, he stretches out beside her, even if he is far away, too far to touch. "What are we doing, Natasha?"

"I don't know," she says, because everything else she can think of is either too much or not enough of the truth; trying to save each other hits too close to the bone, trying to connect in the only way we remember how is only a fragment, too far from the whole of it. She half suspects they're both just waiting on the edges of the group to be lonely again, waiting to leave and be left, and she wonders if he knows it too, if he really knows just who and what she is, even now.

"Have you ever been afraid of yourself?" he asks, his voice sounding so bleak in the darkness that something inside her aches, some tiny bit of red she'd long thought wiped out.

"Every day," she says, staring at the ceiling so she won't have to look at him, won't have to watch whatever's left for her in his eyes change. "I used to kill people and not ask why. And I know what it is to have someone else in your brain, to never be quite sure of whether you're really who you think you are, or if you're just fooling yourself."

"I used to think I was a scientist," he says, and she closes her eyes.

"I used to think I was a ballerina." Once, in another world, maybe they could have been normal people, and had normal lives on opposite sides of the world, each never knowing the other existed. She isn't sure anymore if that would be better or worse.

"We're the same," he says, finally, and she feels the brush of his fingers over the inside of her wrist, over the throb of her pulse, steady even as she shivers. "That's why he's afraid of you. He sees us in you, everything that's wild and dangerous caged up." When she opens her eyes, he's right there beside her in the dim light, solid and real and completely impossible; but of the few things she's ever been afraid of, impossible isn't one of them. "We match, and he knows it."

Which parts of us match, she wants to ask. What if it's only the parts we know are real, the red and the green?

But she doesn't; she rolls over instead, and kisses him, and orders Jarvis to go dark.

In the end, he doesn't turn green, and she doesn't see red; only white, bursting bright behind her eyelids.

x-X-x

It's a week later when the call comes in, about a terrorist cell with dirty bombs and chemical weapons stashed in some warehouses on the water.

The mission turns out to be almost pathetically easy, with Thor and Tony rounding up most of the bad guys before the rest of them even hit the scene, leaving the team with little more to do than go through the warehouses looking for stragglers and confirming the location of their weapons.

"Looks like you might as well have stayed home," Natasha tells Bruce as they edge their way around rusty remnants of shelves and scaffolding in the building's dim, dusty interior. "We didn't even need the big guy today."

She hears the soft, shuffling sounds a second too late, with only enough time to grab Bruce on her way down as a bullet whips over their heads.

Careless, she curses herself as she rolls behind cover. Distracted, stupid. There's a blaze of gunfire off to her left, from a bit of scaffolding – sloppy, she thinks, not really aimed at anything in particular – and from there it's just a matter of running and diving and finding the perfect angle, before she gives up on trying to shoot him and simply climbs up into the network of beams and pipes overhead until she can drop down behind the shooter, and end him that way.

It's only then that she remembers Bruce, and she's halfway back down to the main floor when she hears a familiar roar and stops short, terror washing over her like a drowning wave.

He won't hurt you, she reminds herself as the Hulk lumbers into view below her, moving slowly, suspicious. He knows you're on his team. He does.

Still, that doesn't stop her heart from skipping a beat when he looks up at her and sneers.

Relax, she thinks, forcing her body to be lax, forcing the fear out of her head. It's still Bruce. Do this for him.

"Hulk," she calls down to him. "It's okay now. The bad guys are all gone. You can let Bruce come back now."

"No," Hulk rumbles, almost casually slamming his fist down into the floor, leaving a two-foot wide crater behind. "Banner belongs to Hulk. Not for red woman."

He's jealous, Natasha realizes, her body working almost on autopilot to jump up into the beams above as the Hulk smashes the bottom of the staircase she'd been standing on. Right then, she thinks, hopping from beam to beam as he leaps up into the scaffolding behind her, the structure creaking in protest. Don't be afraid, he doesn't like fear. Be like Bruce. Be angry.

"You want him?" she yells, swinging around to face the green monster at her back. "Then you're gonna have to fight me."

She thinks that must have confused him, since he reaches out for her almost lazily, rather than just outright smashing.

"But I don't want to fight you," she calls, swinging away, getting up enough momentum to fly through the air to the next beam. "I want to trust you. I want to help you."

"Help?" Hulk roars again, and suddenly she's not so much flying through the air as plummeting down, batted from the heights like a bird with a broken wing.

He catches her before she hits the ground, though Natasha isn't certain that being squeezed in one giant green fist is much improvement over being splattered on the concrete. "Help how?" he growls, his black eyes pinning her, full of incomparable rage.

She tries to breathe as shallowly as possible, feeling his huge fingers tighten around her ribs with every breath. "Because," she grits out, feeling a sharp stab as one of them cracks, "I will kill anyone who tries to hurt Bruce."

"My job," Hulk says, and lifts her up, ready to smash.

"No!" she screams, bringing her fists down against his fingers as hard as she can, even though she knows it's a futile effort, a butterfly beating its wings against a tank. "I can do it even when he won't let you!"

She expects to feel nothing; the air whipping past her face before an abrupt stop, maybe. Instead she feels the iron grip around her chest ease just a bit as he brings her back down to eye level.

"Work with Hulk?" he mutters, glaring at her with what, for the Hulk, might pass as a friendly look.

"To protect Bruce, yes," she says, looking him straight in the eye, trying with everything left in her to convey, I am not afraid of you.

The Hulk snorts and releases his grip, leaving her to fall to the floor before wandering off around a corner.

This time, she doesn't need several minutes to recover herself; all she needs is the time to get her back against the wall so she can sink to the floor, trying not to breathe too deeply, before calling in the others and closing her eyes.

x-X-x

If Natasha had gotten her way, she'd have been able to isolate herself from the others for a day or two; long enough for the bruising to fade and her lungs to expand without screaming at her.

Nobody gets that kind of luck (or privacy) in the Tower though, and of course it's Bruce who finds her on the edge of her bed, hand pressed to her ribs, hissing in pain.

"He hurt you," he says immediately, his voice flat. Angry, she thinks, but whether at her or at himself, she can't decide quite yet. "I knew it."

"I'll be fine, Bruce," she promises, trying to wave him off. "I'm a big girl, I can take it. Plus, I heal up pretty quickly. I might not be quite up to Cap levels of toughness, but I'm harder than Clint." She expects at least a smile for that one – Clint's recent dislocated shoulder had been the source of at least a week's worth of melodramatic whining to anyone within earshot – but Bruce's face stays frozen, his eyes hard.

"Show me," he says, adding, "please, Nat," when she shakes her head. "I need – I have to see. I need to face it."

"Fine," she says, because she knows this will never get any easier, that there's more between them than just a few bruises; this is the other half of her bargain, the price to pay for the memory of having him inside her, for the look on his face when she had been certain that for one sweet moment, he wasn't angry. So she stands, pulling down the zipper on her suit, easing it first from her shoulders and then, with more difficulty, over her hips, until she's able to step out of it and stand in front of him in just her underwear and the colors of her skin.

That it looks bad she already knows – she can see the bands of livid red darkening into purple around her chest, from her breasts to her hips – but from the look on his face, Bruce clearly thinks it looks more than just bad.

"Natasha," he breathes, running a hand through his hair. "I'm sorry." And just like that, he turns to leave.

"Hey!" she calls. "That's it? Where are you going?"

"Don't you think I've done enough for you today?"

"Bruce," she says, catching up with him before he can reach the door, "this wasn't your fault. This was the Other Guy. And it's okay, we made a deal."

"You made a deal with the Other Guy?" he asks, his voice still flat, still looking towards the door. "What, you run fast enough and he won't smash you into paste?"

"Hey," she says softly, reaching out to touch his face. "Look at me. We're okay now, I promise. We are okay." It isn't enough, she can tell; he isn't relaxing into her touch, hasn't made a move towards her. The muscles of his jaw flex under her hands, hard and tense and so very, very angry.

So she does the only thing she can think to do, even though half the muscles in her body scream in protest; she pushes herself closer to him, and up just a tiny bit, just enough to whisper in his ear.

"I'm not afraid anymore."

He takes a deep breath, and she feels his shoulders go slack, senses his hand sliding from the doorknob. "I am," he says, his voice muffled, face buried in the curve of her neck.

"Well," she admits, pulling back and taking his hand, "I might have exaggerated a little. I'm not afraid of the Other Guy anymore. That doesn't mean there aren't other things I'm afraid of." When she squeezes his hand, he meets her eyes, at least; it's not much, but it's something. "Maybe I just need a little more exposure therapy."

He follows her meekly enough to the bed, and shucks his shoes when she looks down and raises an offended eyebrow at them, but she can tell his mind is still working, impossible to turn off, even as he settles in gingerly beside her, still unwilling to touch her, as though his human hands are capable of as much damage as his monster's.

"Do you ever wonder if we were all better off alone?" he asks.

It would be a lie to say she hasn't wondered, to say she hasn't been certain of it at times. It's easier to be accountable to no one, to worry only about yourself, to not be anyone's backup, anyone's liability, anyone's weakness. Easier, but with every day it's harder to imagine ever going back to it.

"It's easier to lose yourself when you're alone," she says. "Maybe that's why it's good to be part of a team, to have somebody else to remind you of who you really are."

He looks down at her body, laid bare and open to him, and traces one finger along the dark streak over her hipbone, so lightly she barely feels it. "What if I don't want to be who I really am?"

She shrugs, and smiles, as honestly as she knows how to, and forgets to think of risks. "If you're a monster, so am I. At least we can be monsters together. We match, right?"

"Right," he says, and looks back at her with perfect brown eyes, not a hint of green.

She stifles a yawn, and shifts herself closer to him, feeling his hand come to rest on her shoulder, fingers splayed warm over her skin. "You smell good," he says, mouth against her hair, and at least for now, Natasha is content.