A/N: I have read that the actors play Esposito and Beckett as though they have a past, and I tend to believe this. This is what I think that past is.
Esposito is a slow burn. She recognises this. She recognises herself, in him. The anger. In his case, it's slow, steady, hot. She doesn't know what happened to him. And she doesn't really care. She's heard the rumours about the 54th, knows he's done a tour or two. Sure. So she knows, but she doesn't know. He's Hispanic, sure, so she could make a few cultural assumptions, as well. But she doesn't. Because if anyone knows how deceiving appearances can be, it's Kate. Nice girl. Cute. Manhattan accent. And she's none of those things. Not anymore. So no, Kate doesn't know what happened to Esposito, and she doesn't care, and she's not going to ask.
The point is, he's angry. That's undeniable. A slow burn. And she's angry, too, to the point of combustion. At work it drives them, pushes them both to be their best. In a raw fight for justice, their anger messes with them, blurs the line between justice and vengeance.
She was at the twelfth already, when he arrived, a veteran in the homicide team. Or so she figures, anyway. She feels like a veteran, most days. Being a veteran, though, doesn't stop the cases from hurting. It doesn't stop her heart being heavy and it doesn't make going home alone any easier. But she doesn't mix business and pleasure, so on the days she doesn't go home alone, it's not with anyone she'll ever see again. She learnt that lesson from her training officer.
They work well together. Everyone knows she likes the weird ones, and she can't even begin to tell them why. Because they distract her. It's fascinating to dive into the ones that everyone else pushes into the too hard basket. The more interesting the cases are, the easier it is to sleep at night. A domestic gone wrong? The mundane hurts her, in a way that the weird ones don't. It probably shouldn't be like that, but it is. And Esposito gets a kick out of Kate's fascination with the weird. Beckett flavoured, they call them.
Kate's life is divided into before and after. Before, when she was a teenager, a child, she'd been wild. After, too. After, though, there was a self destructive edge. But before, she remembers her Dad telling her how he'd met her Mom. Before, when she was a teenager, she'd assumed that when she met someone, everything else would be stripped away and she'd know, and so she looks at her parents' relationship with a kind of reverence. That's how her Dad told her it would be, when he had talked about her Mom, talking her down off the ledge of a doomed teenage relationship. Kate no longer has that blind trust of her one day, or her happily ever after. But there's a nagging voice in her heart that wants to believe. And that voice tells her- she and Esposito would go up in flames. Tells her to not even go there.
Kate thinks she'll never go there with a colleague again, anyway. She has plans, goals, ambitions, and she's not going to be the person who can't keep their personal life and work life separate. Sure, sometimes lines blur. But she doesn't want to let them. She does love what she does, though, so if she found someone who got it, well, that wouldn't be so bad. If she was pretty certain.
So rough case, after rough case, Kate and Esposito find a routine. She's no stranger to bars and alcohol. Neither is he. Her college days aren't that far behind her, and they've put her in good stead for handling alcohol. Kate's pretty sure he doesn't have anyone to go home to either, but she never really checks. They don't talk about that kind of thing.
Kate's a little apprehensive about drinking too much these days, but still, an after work drink to take the edge off? She's not that worried, won't be concerned until she can't make it into work. The way her Dad stopped making it into work. So they have a quick drink after the harder cases, sit next to each other at the bar, or in a booth.
Kate prefers it when they sit at the bar, because it's harder to cross a line, that way. And whenever they end up in a booth, she always thinks they will sit on opposite sides, this time. They never do. Their legs press together, and she's always way too conscious of his thigh pressed against hers. She pretends she doesn't notice how closely they're sitting. And Esposito never says a word, never does anything untoward, nothing that would label them as anything more than friends who occasionally have a drink together. When others from the squad come out with them they don't sit together. Or if they do, it's actually by chance, and there's no touching then.
And one night it happens. It's been building for a while, months of verbal foreplay. Looks, meaningful. That they both deny. Because no, hell no. They're just friends. Actually, Kate thinks Espo is as smart as she is. He knows it would never work either. But there's a funny attraction there, something that draws them together.
His leg is against hers, and just one more drink, and God it was a rough case, today. And the just one more spills into another, and his hand is on her thigh, and they both pretend like it's just the alcohol, like really, he's just steadying himself. But that's the bitch of it. He needs someone to steady him, and that won't be, cannot be, Kate. She's as unsteady as they come, disguised neatly behind her heels and choppy haircut and sassy mouth.
He leans in, and she's leaning in, meeting him in the middle, breathing in the what ifs and if onlys and his breathe is hot against her and his lips are warm and his tongue is rough and she's moaning helplessly into his mouth and inside her heart is breaking. They pull away from each other, their eyes meet ruefully. When they walk away from each other to catch separate cabs, for a split second she thinks about calling out to him, going home with him. Giving in, just for one night. She doesn't. It's not pride. It's a tiny bit of self preservation she didn't know she had.
They don't go out together after work so much after that, and if they end up alone, they actually sit on opposite sides of the booth. Or at the bar. It's harder to cross lines that way.
When Ryan joins the team, he's like a ray of sunshine on a cloudy day. Not that she would ever tell him that, not ever. But he changes the dynamic of the team when he's paired with Esposito and Kate's heart is lightened, just a tiny bit. Ryan is like a brother from the start, the way Esposito never was. She would never consider going there, not even for an instant. But there's a part of her that recognises the kind of man Ryan is, and appreciates it. There's a stability to him, and she wonders if he knows he is a grounding force not only for his partner, but for her.
She misses her father. Right now she has the Captain, and she has Ryan. It is what it is, and she when she meets Will, he's a good man so she accepts a date with him, and another and another, until she thinks maybe, just maybe, she could be all in. When he leaves, she guesses she wasn't quite as in as she thought she was, because she misses him, but just not as much as she thinks she should.
Much later, when Esposito hooks up with Lanie and they're so painfully obvious about hiding what is obviously a relationship? Kate's grateful. God, is she grateful that Lanie can be for Espo what she herself couldn't. And she's so grateful that even at her dumbest, she wasn't that stupid, that she didn't inadvertently screw something up between two people who have become her best friends. She didn't go there. The two of them are still similar, he's a slow burn, angry, and she's all too combustible. God, she's glad that even though she and Espo flirted with the line, they never truly crossed it.