Kate Beckett remembers how this feels. This waterfall in the ears, this absence of heartbeat and breath, this forgetting how to move. She also remembers that if she doesn't breathe soon she's going to find herself on her knees trying not to lose everything she's eaten in the last twenty-four hours. She knows this because she's been here before. It's about your mother. Word for fucking word, the only difference is the voice.

Whatever Castle is saying now - and he must still be talking because he keeps moving his mouth - doesn't really matter. She can't hear it over the rushing water, can hardly see him through the sparks beginning to appear before her eyes. Somehow she manages to get her feet to move, and if she can just get past him, everything will be all right. But he doesn't let her go and she's no longer a nineteen-year-old girl with arms like limp spaghetti; she's a grown woman trained for the streets and even with her mind in freefall, her left hook is still damned good.

She doesn't wait to see if Castle goes down after she hits him, and she still can't hear so she misses the thump when he does. Misses the plaintive cry that follows her down the hospital corridor and out the door. Misses him already, whatever it was he was beginning to be to her, but that's gone now so she just walks, confident that these two things are connected, the walking and the breathing, and the breathing means she can manage the next thirty minutes on the subway without hitting anyone else.

It's not until she's home and safe behind locked doors that she realises three of the fingers on her left hand are blue and swollen. No matter how well trained you are, it's still a bad idea to punch someone barefisted in the jaw.

0—0—0

They're waiting for him right by the goddamn door when he gets home, his mother and his daughter, twin fonts of redheaded disapproval.

'Well?' his mother finally demands, after he's shut the door and shouldered through them on his way to his drinks cabinet. 'How did it go?'

Castle concentrates on the tiny key on his keychain which fits into a tiny lock, his vague attempt to keep his mother out of the best of his stash. She can probably pop the lock with a hairpin, and probably already has. Involuntarily, his tongue moves to check the right side of his mouth. There's a cut on the inside of his cheek which is annoying him, and his jaw is incredibly sore, but he'd had hold of Beckett's right arm and she's not a southpaw, so his teeth are still miraculously intact.

He pours himself a triple shot of Isle of Islay, and nearly chokes trying to down it all in one. He has to hang on tight to the edge of the bar as the alcohol burns first his esophagus, then his stomach, and only then - like a gangster carelessly tossing a match into a pool of gasoline as he exits the scene of the crime - sets the inside of his cheek on fire. Funny how it should happen in that order. Kind of like Beckett's reaction to his meddling in her mother's case. By the time he'd processed the fact that she'd just knocked him flat on his ass, she was already gone, and for once in his life he'd had the good sense not to follow. Hence scotch and disapproval, not necessarily in that order. Not that he blames Kate Beckett one tiny bit. He'd just punched her in the gut - metaphorically, but the distinction doesn't seem worth bothering with - so it only seems fair that she'd punch him back.

'Oh,' his mother says, finally understanding that Castle's sudden need for alcohol is his answer, not that it should have taken her this long. 'Well, give her some time. She'll cool off.'

'She's going to have all the time in the world.' Castle pours himself another two fingers of scotch, taking care to keep it on the other side of his mouth as he gulps it down. 'My all access pass has been revoked.' Which is the one thing in all of this he desperately, desperately regrets, the one outcome he hadn't considered. He'd wanted to get closer to Beckett, wanted to be the one to give her what no one else could, not even herself. Instead, he's driven her as far away as it's possible for two people living in a 28 square mile city to get.

'Don't worry, Dad.' Alexis pats him on the shoulder. 'I'm sure you'll be able to talk to her when she calms down.'

And worst of all, now he finds he can't look his own daughter in the eyes. 'I'm sorry, Pumpkin. I know you like her, but I don't think we're going to see Detective Beckett again.'

'Dad, you like her. Like, like her like her. And she likes you back.'

'That doesn't matter.' He takes a deep breath and finishes the scotch. 'Sometimes people do things that can't be forgiven, no matter how much you go on liking them. She's a professional, so she'll deal with me if she's forced to, but she'll never trust me again.'

He has to sit at the thought of that loss. Of Beckett pulling a thin chain out from under her clothes, her mother's ring balanced on her fingertips, giving him the gift of her story, unbidden. He'd thought trying to solve her mother's case would show he cared for her beyond literary inspiration, that he understood her pain and admired her for what she'd made of it, instead of letting it pull her under. Instead, he realises now, he's only shown her that he's never understood her at all.

'What you did, Richard,' his mother says, in the same tone she used when he was nine years old, 'it was wrong, but you did it out of love. A part of her knows that, you just need to remind her of it. Because whatever your Dr. Death found, when she stops being angry she's going to want to pursue it, and she'll need you with her when she does.'

'She doesn't need me, Mother. She got through it alone when it happened, and now she has other people if she needs help. Better people for police work.' He steps back, removing himself from Martha's reach, and grabs the rest of the scotch. 'She once said I didn't know the difference between being a wiseass and a jackass and she was right.'

'Richard! What are you planning to do?'

'She told me to leave her alone. So for once in my life, I'm going to do what I'm told.'

He escapes inside his study, firmly locking the door. The bat cave, Beckett had called it that first time, walking around as if she was afraid she might break something too expensive to pay for. She'd been the most valuable thing in the room, but he hadn't realised it then and she probably never would. The touchboard outlining the new book is lit, as always, just in case he has a sudden bright idea. He walks over and frowns at the picture of Beckett-as-Nikki, a moment stolen without her consent. At the time, he'd hadn't thought of it like that, he'd only wanted to capture the double crease of concentration between her brows. Now he knows it's the same crease she gets when she's angry and confused, when she knows who's guilty but still doesn't know why.

Castle strokes the various bits of plot open and closed, and then, with one grand sweep of his hand, he gathers it all together and wipes Nikki Heat off the board.

0—0—0

What with one thing and another, Javier Esposito is convinced that this summer is going to be the longest three months of his entire life.

First, there's the heat. Crime in New York City is directly proportionate to how hot it is outside, and how long it's been since the last good rain. At least, that's what Ryan swears, and with the workload they currently have, Esposito has no reason to doubt his logic. Then, there's Beckett. Or rather, the absence of Beckett. There's someone who looks like Beckett sitting in her chair, hovering over the board, out in the streets solving crimes for all she's worth. To the untrained eye everything probably looks fine, but she's been ordering Esposito around for the last two years and he can tell when her heart's just not in it. It's like when Sorenson left for Boston, only ten times worse because Esposito knows her now, and he knows what she's like when she's okay. This...is not okay.

For one thing, she's being polite. She says please and thank you and do you mind. She asks him what he thinks and sometimes even lets him take the lead...if his lead is heading in the same direction as hers, of course, but still. She doesn't call him in at ridiculous hours or on his days off, she works the overtime herself. And when he teases her she either teases back by rote, or looks at him like she hasn't understood, like he's distracted her from some other thought. Or worst of all, makes her face smile without actually getting inside it.

'How long you think this is gonna go on?' he asks Ryan, who's hiding his own face behind a pile of unfiled paperwork.

'What?' Ryan asks, without looking up from his keyboard. He's in the middle of hunting for a letter, index finger circling like a hawk looking for a mouse.

'Jesus, take a typing class,' Esposito huffs. 'You know what.'

Ryan's eyes lift, meet Esposito's over the monitor, then sidle to the right, where Beckett has been staring at a file without turning a page for the last fifteen minutes. 'You gotta let her figure this out for herself,' Ryan says, and goes back to the hunt.

Esposito flops at his desk, dragging a pile of his own paperwork over. They're between cases for the first time in weeks, which is probably making being around Beckett even worse. Routine form-filling is nowhere near distracting enough when you need serious distraction; Esposito knows this himself from his last couple of relationship bust-ups. Though to be honest, he's never been too cut up. Neither has she, he feels pretty sure. It's not like they trade heart-to-hearts but there's a certain way you get to know people on the job, how you tell each other stuff without ever actually talking about it. He rode shotgun with Beckett a whole year after Sorenson, and yeah, he was the new guy so she wasn't giving away much, but he still doesn't remember her being anywhere near this cut.

And he can't help waiting for the other shoe to drop, for her to finally figure out that he's the piece of shit who betrayed her by letting Castle get his hands on her mother's file. Not that he had expected Castle to actually remove the fucking file from the precinct and give it to some pathologist to dig through. And then to go and tell Beckett all about it. Hijole, the man could be a brainless idiot sometimes. Sure, he only meant to help, and sure she paid him back good - Esposito saw the massive bruise on Castle's jaw when the man crawled in to give him back the file, so the reason for Beckett being out for two days, then coming in with her left hand in a splint wasn't exactly a mystery. Or a surprise. Maybe the only surprise was that she'd used her left, and Richard Castle better be thanking his lucky stars for that, cause if she'd used her right he'd have probably found himself sucking steaks through a straw.

0—0—0

She's dancing when Will gets to her apartment. Second time this week. Not that he doesn't like to see Kate dancing - she's surprisingly good at it so yes, he likes it, in fact very much. He just knows that taken in context, it's not necessarily a good thing.

Some cops drink, some do drugs, some just let it all build up and die of stress a year after they retire. Kate dances until she drops. He knows this from their first time together. When things were shit at work, when there was a case she couldn't close, when some jerk was giving her hell for being female and she had to laugh it off, when her Dad called and talked in circles for an hour never asking how she was doing herself, when the holidays were coming, or her birthday, or the day her mother died, or the two of them were very carefully not talking about Boston, then she would put on a pair of earphones and blast herself into some other mental space, arms and legs flung about in a strange sort of rudeboy retro that didn't belong to what he thought of as Kate. She'd told him once that she'd gone punk in college, before her mother died. Looking for drama, she said, and then drama found me and it wasn't much fun. She'd had to show him the one picture she still had from those days to make him to believe her: dyed black hair in ratted hanks to her waist, a racoon's mask of makeup painted around her eyes. It was like looking at a repli-Kate from an alien world, so different from the serious, subdued woman she'd become.

And now the alien is here, with her eyes tight shut and an iPod he didn't even know she owned until two days ago clutched in her hand, dancing around her living room with a ferocious, silent grace. She's taken off her coat and her boots, but apart from that, she's still in her work clothes, and maybe that's what's making the picture look so wrong, maybe it would look less strange if she were dressed for a club. One more reminder that as much as Will thinks he knows about Kate Beckett - and they were closer that first time than they'd ever been to anyone else - he hardly knows her at all.

She bends over to catch her breath, hands on her knees and sweat dripping off the end of her nose. She hasn't heard him come in, and he wonders if it would be better to back quietly out and call, if she'd even hear the phone. Or better yet, come back in an hour when the alien has departed, and Kate has showered and changed and returned to the woman he knows.

But it's already too late; she's opening her eyes, suddenly alert to the fact that she's not alone. Sorenson waves, feebly. Sheepishly. She takes the buds out of her ears and he tries to figure out what she's listening to as she comes closer. A woman singer, a band heavy on drums and bass guitar. Something more contemporary than he was expecting; he's heard it before, but can't identify the song.

The music plays between them as she stops in front of him, flushed and breathless, and little Will gives an approving salute. 'Bad day at the office?' Sorenson asks. She even doesn't bother to answer, just takes the last step forward and glides into his arms.

Ah, this. Now, this is the Kate he understands, this is the form of stress relief they usually share. Of course, it usually takes him a little longer to get her this hot - literally hot, her skin damp and feverish under his hands - but with the way she's moving as she kisses him, still in time with the tinny music coming from the earphones, he's catching up pretty damn fast.

'So, cancel the dinner reservations?' he says, when she finally lets him break for air.

'It won't come out,' she answers, resting her forehead against his shoulder. It's what she does when she doesn't want him to look her in the eyes, which can only mean that this is about that thing with Castle again. 'I'm so goddamned restless and it won't come out.'

In this state, he can't tell if her breathing is erratic from the dancing or from something else. She's never let him see her cry, he's fairly sure she wouldn't want to start now. 'Listen to me,' he whispers against her hair. 'You need to talk to Castle. You need to find out what else he knows and put this damn thing to rest.'

'No.' Her voice is muffled by his shoulder. 'It'll just make me crazy again.'

'Babe, I have news for you. It already has.'

The fact that she burrows further into his arms instead of taking umbrage only proves that he's right, and suddenly he's scared. By the time they met, three years ago, she had come through her mother's death, battle-scarred but triumphant, with a shiny new promotion to homicide hanging from her belt. He had found her easy to be with, quick to laugh, and if she had her darker moments, times when she was clearly upset and wouldn't let him near, there were also times when, in the right mood, she would tell him things that let him understand her, bit by bit.

And he had loved her for all of it. Too bad he'd had to go all the way to Boston to figure that one out.

'Talk to him, Kate. At least if he's really got a lead, you have something concrete, something you can pursue. This is just battling shadows.'

'I can't open that up again, Will. You have no idea, you weren't there.'

'But I'm here now.' He doesn't want to let go of her, but he needs to see her face. Her eyes. 'I will see this through with you, Kate. Whatever happens, however long it takes. I swear.'

Her eyes are darker than normal, rimmed with red. But no tears. It makes her look intractably stubborn, and that's the Kate he knows. 'You can't make that promise,' she says. 'You have no idea how long this could take, or where the Bureau will want to send you in the meantime. What Castle's found, it could be coincidence, it could lead nowhere. Or it could lead to something that takes years to unravel. You can't swear to be here.'

There are things that he could say to that. He could say marry me, because if there's one thing the bureau's been pushed to do in recent years it's to acknowledge that female spouses also have careers, and moving posts on a biannual basis is not generally conducive to a happy marriage. He won't get as far, or as fast, as he would have if he'd stayed single and mobile, but he won't be punished for turning down an offer because his wife - incidentally also a law enforcement officer - has a job she isn't willing to leave. And maybe in a few more years, when her twenty's come up, she'll be ready to move on. Maybe by then there'll even be kids.

He could ask, but he's pretty sure she'll say no, even if they both once thought they might be married by now. And that would be the end of them, before they could even start again. After two years of wondering if leaving Kate Beckett was the biggest, stupidest mistake of his life...well, he hadn't expected to find her still single, and now that he has, he doesn't want to make that mistake again.

So really, if she wants Richard Castle out of her life, wouldn't he be an idiot to object?

0—0—0

Castle's resolve lasts a week, maybe two. The truth is, he's never been very good at abject, even less at guilt. Poverty's not his style either, and the grand gesture of putting Nikki Heat to rest is very quickly countered by a long conversation with his accountant about the possibility of paying back his advance, after a very short one with Gina about breach of contract.

Fortunately, he tends to back his work up on a number of disks, not to mention online storage, the result of one not so fortunate night-before-deadline loss of a laptop several years ago. Between that and his scrawled notes, it isn't long before Heat Wave is reconstructed and back on the board. Two months later it's delivered, signed and sealed, and his daily reminders of Kate Beckett are gone.

He can't say he knows what to do with himself after that. In the interval between completion and getting the galleys back to correct, he takes to wandering the streets, looking for inspiration for his next book. It's there he sees her, a couple of blocks from the precinct house, an area he generally tries to avoid. She's got the badge on her belt, and she's with Esposito and Ryan, but they're not working a crime scene. They're just four people grabbing a quick lunch from a Sabrett's wagon, and if his heart does a one-and-a-half gainer before it hits bottom hard watching Will Sorenson bumping Beckett's shoulder and making everyone laugh at one of his crummy jokes, well, he can just put it off to not having seen Kate Beckett in a while. And when Paula calls, not ten minutes later, to tell him that Cosmo wants him for a cover to precede the book launch, well, he can't really be blamed for suggesting that the best venue for the photoshoot would be exactly where Nikki Heat was born...inside the homicide room at the 12th.

0—0—0

It ends with Will exactly the way Kate thought it would - an offer he can't refuse, a proposition she can't accept. This time around she doesn't even bother crying in the bath. She's still hopeful enough to be fooled once, but not by the same man twice; she's not sure where she and Will would have ended up even if he had decided to stay in New York.

But Castle...Castle is another matter. Will's mirror opposite, the one who won't stay gone no matter how many times she sends him away. And when he comes back yet again, and stands at her elbow to say, at last, that he understands what he did and he's truly sorry for it, the only thought she has left in her head is she'd never expected this.