It was an accident, the first time she sees him. She's staking out a dead drop in Singapore when she catches a glimpse of tan skin and unruly brown curls attempting to escape a purple baseball cap. Natasha is careful not to get her hopes up. This is the third time she thinks she's seen him today. Half the time she'll see him out the corner of her eye, but when she looks there's no one there. Just a figment of an imagination in overdrive.

She watches him shuffle around the market. He's almost instinctively aware of each ebb and flow of the crush of humanity that is packed into this sweltering pit of shady bargains and pickpockets. He sways with the bustle, just enough to avoid each jostling shoulder and flailing elbow. Almost as if he knows it could be disastrous if he did get shoved. He weighs a mango in his hand, the other jammed into his pocket. His face angles slightly more towards her as he chats to a trader. Natasha takes a sharp breath.

It's Bruce. He buys the mango, and some other groceries, and although she tells herself not to follow, she does, shadowing him as he meanders through the market. She knows that she's staring, but for once she doesn't give a damn. Her heart is hammering, her breath seeming not to fill her lungs. She wonders if this is what it means to truly care.

He ambles from vender to vender. At one point he stops, turns, and peers around, and she thinks that she has been made. Natasha laughs humourlessly to herself: the formidable Black Widow undone by a crush. He pushes his glasses further up his face, and she presses back into the shade of the van she's shielding herself with. He seems satisfied with his brief scan of the street, and starts packing his shopping into the luggage compartment of a motorcycle that she hadn't even noticed was beside him. Sloppy.

Natasha knows this is it. She evaluates her options. Confrontation, or evasion. Her skin is flushed and her fists clench as she practises the calming techniques she's been taught, but never needed. She tries to find the nerve to go over there and say something. Anything. Just take a step. He'd notice her if she took a step out of the darkness, this she doesn't doubt. And then all of a sudden it's too late, and the motorcycle splutters away.

She pretends that her heart doesn't sink.

He's probably happier like this, without her.

The second time she sees him she's doesn't recognise him, not at first. Partly because his face is the last thing she's expecting to see on a SHIELD tablet, and partly because it's more a mugshot than a picture, one of those horrendous photos that are taken against a blank wall, the company photographer demanding that you 'say cheese'. There's a buzzing in her ear and she realises her new handler is droning on about the protocols needed for training the man that turns into The Hulk. It fades into white noise as Natasha carefully places the tablet down, and strides out. There is no noticeable sign of distress on her blank face. She is the Black Widow after all. She has no emotions.

The third time she sees him, she hears him first.

Since she learned that he was back at Shield, she's been taking every single over-seas assignment available. Between missions she prides herself on being exactly where he's not. Fury had refused to give her a new handler (oh how she missed Phil). Charles is a pompous bureaucrat who pretends that he isn't scared of her. He compensates for it by making sweeping comments about women's place in the workforce. Sometimes she thinks she'd be doing Fury a favour if she removed him. Natasha had just extricated herself from his clutches, and was storming along the corridor to the gun range. At least she can kill a cardboard cut-out.

But she'd been careless.

Bruce's voice bounced along the corridor ahead of her. He's about to round the corner, and walk straight into her. Without a second thought she plants one foot against the wall, springs off it, and flips herself round a rafter into one of Clint's nests. Banner's engrossed in a conversation with Stark about inverse Compton scattering. As he passes below her, he pauses and looks about, seemingly aware of being watched. She guesses his senses are well honed from being on the run for so many years. Stark, impatient as always, nudges him. He mumbles something incoherent, shakes his head, and continues where he'd left off. Natasha lets out a breath she didn't realise she was holding, as she watches him disappear from sight.

"Ouch." Grumbles the rafter she'd landed on. Natasha stares down, bewildered, at Clint. He grins cheekily up at her.

"That was some intense evasive action." He snickers. She shuffles off him, and they sit up against the sloping roof. His face gains a more sombre tone. "I guess you haven't spoken to him yet." She grimaces.

"No."

"He's been telling everyone how sorry he is." Clint fingers the grip of his bow.

"But not me." She says, and immediately regrets it, because she sounds whiny and petulant.

"Nat, he can't even find you to apologise! I've even sent him in your direction a couple times." He's half frustrated, half amused. Natasha wrinkles her nose.

"I know. I hacked his phone so I'd always know where he was. So I could avoid him." Clint stared at her, seemingly lost for words. She can't meet his eyes. He suddenly snorts with laughter. It's infectious and then they're both in hysterics over how ludicrous she sounds, and Natasha doesn't think she smiled this much since Stark's party, before it all fucked up.

The fourth time she sees him she's stalked him to London.

Natasha loves London. It's easy to hide in plain sight. The British are the perfect mixture of polite and awkward. They respect her personal space, and would be mortified to be caught staring. Londoners, in particular, are wrapped up in their own little bubbles and she feels invisible, safe. She could be anyone, anything and still manage to blend in. Today, she's a cocktail waitress. She grins at the symmetry in spite of herself. "How does a nice girl like you end up in a place like this?"

Tony's just given a speech pledging his money to a charity that encourages children to get involved in science, and is urging his guests to do the same. Bruce is standing to one side of the stage, out of the limelight, in a suit that Natasha is certain Tony will have coerced him into. He looks good, but slightly uncomfortable. He pulls at his collar absently, before realising he's doing it and crosses his arms instead.

When he's called onto stage, Natasha's impressed with how well-spoken he is, even if he does wring his hands one too many times. The guests are mingling now, and she knows that's her cue to walk around with a tray of drinks.

Natasha had a plan. She'd been ridiculous enough already. This was it. Natasha had brought down nations, ruined countless lives, and even tricked The Trickster. She could handle one man.

She was going to walk up to him, say something witty, reminisce perhaps. Maybe they'd play the same game, pretend like nothing had happened, that nothing had changed.

But that wasn't true. And they'd both know it.

She'd even considered dumping a glass of champagne over his head. Tony would love that.

But she didn't.

Instead, she leaves out the back entrance, and disappears into the night.

The fifth time she sees him, she's pointing a gun at his head.

Natasha doesn't like open doors. An open door means someone could waltz straight through, nothing to announce their arrival. An open door means there are no secrets behind it, or at least none worth keeping. And what good is that? However, Natasha especially doesn't like open doors when they are swinging half off the hinge, splintered at the lock, just like her front door is right now.

Gun already drawn Natasha pauses outside, calculating how many people want her dead. The numbers aren't great. But the number of those that can find this apartment? Either she's getting sloppy or she has got a massive problem. Neither option is appealing. She inches forward, trying to peer inside to see if the intruder is still here.

Natasha freezes as she hears the tinkling sound of china smashing, and a curse muttered under a breath. Who on earth has the skill set to find her apartment, but is inept enough to be so noisy whilst breaking in? No-one. She comes to a laughable conclusion. She, the Black Widow, is being robbed. They'll soon learn the error of their ways. She lives in a bad estate (not exactly a problem for her, and it's cheap), which explained why nobody had bothered to investigate the sound of her door being kicked in. Being too nosy in this area is dangerous (for someone else).

She slips past the wreckage of her front door, gun still drawn. One can never be too careful. It sounds like her thief is attempting to make a cup of tea. The audacity! She listens for a sign that there's more than one intruder in her house, and clears each room except the kitchen, in which this bumbling fool is banging cupboards and clinking mugs. Although he obviously has no espionage skills, this man (92% of incarcerated criminals were male) had managed to break down her door, which was no mean feat. She's not going to give him a chance to fight back.

She hears him open the door to her fridge. Perfect. She visualises the kitchen. Plans her move.

Natasha spins into the room, kicking the thief's legs from under him, and yanks his shoulder so he lands on his back with a heavy thud. She pins his arms with her knees, and points a gun at a pair of blinking brown eyes, a tinge of green already fading from their edges.

"Hello," says Bruce mildly.

Fuck.

Natasha thinks that perhaps her heart has stopped. Or maybe it's just beating so fast it feels like it. Her skin flushes cold, then hot as she stares down at him. He shifts slightly beneath her and she's suddenly far too conscious that she's sitting on his chest. She growls, slides her gun away and stalks into her lounge, desperately trying to regain control of herself.

"This is not how I planned for this to go." He follows her, running a hand through his tousled hair, and stands in the doorway. She remains silent. He tries to catch her eyes. When they meet, she's caught in his gaze, and she doesn't think she could look away if she tried. If she wanted to. Her face impassive (she hopes), she closes the distance between them in a matter of steps. They stand there, eyes locked, motionless. Then she slaps him. His eyes stay brown.

"That was for leaving us." He open his mouth to speak. She slaps him again.

"That was for taking so long to come find me." This time his eyes flash a dangerous green. Without warning his hands tangle in her hair, his lips pressing against hers, and Natasha kisses him back furiously. She shoves him into the wall, and prowls over to him, and his hands are digging into her hips as he holds her closer. They kiss as if they can make up for lost time. When they part, panting, to catch their breath, he strokes the pad of his finger down her cheek. She tugs him after her into the bedroom and they tumble down onto the pillows.

"Are you sure?" he says, anxious eyes gazing at her. She laughs. She can't help herself.

"Very," she says, and pulls him down to kiss her again.

After, her face is buried into his shoulder and she looks up at him. He's looking at her like she's a present on Christmas morning.

"You're surprisingly strong." She said, then smirked.

"Maybe not so surprising actually." They both laugh.

"So," she said. In a swift move she straddles him, her hands interlinked with his. He's concentrating very hard on looking at her eyes.

"What happened to my door?" He gives her a sheepish grin.

"Yeah, um, sorry about that. It's just, you've been avoiding me, and I was knocking forever, and Tony said that you were in so… I got a bit angry." She bites her lip.

"I've got it under control though, don't worry!" He scrambles to assure her. It definitely isn't funny. Not even slightly.

"I guess you've got a lot to make up for then." She drawled, arching her back and leaning closer so that their noses are almost touching. He bucks his hips and flips them over, and Natasha shivers with want. He gives her a chaste kiss that leaves her needing a lot more, and smirked.

"I can do that." He said.