Author's Notes: This is something I've been thinking about since I first saw season three. It's not exactly AU, but rather a bit of a re-working. I had decided to sit on it until a lot of it was done, but I figure some accountability might help push me into finishing it. Thanks to – well, my brother, actually, for looking this over for me. Cheers, bro. And Wendy, for her help, even if she'll never read this. *g*

Spoilers: All of Season Three is fair game.

Disclaimer: Castle is owned by the dudes who own Castle, obviously. No copyright infringement is intended and no profit is being made.

the gasp and stutter of a heart 1/?

Rick sucks in a deep breath and ignores the heavy sting of chlorine that burns against the back of his throat.

The flashes of blue and red reflect off the surface of the pool and it's easier than he thought it could be to ignore the chaos of the scene playing out behind him.

The guys are hanging around somewhere, he knows. Ryan was being tended to by the paramedics last he saw, and Esposito's bound to be hovering nearby. Kate – well, he'd lost track of her early on, and that was a good thing, wasn't it?

The way she'd been looking at him – grateful, relieved, like he could be the only thing that mattered – he hadn't been able to handle it because – This? It's his fault at the end of the day, isn't it?

If he'd just figured it out sooner. If he hadn't been so cocky, so sure, to just blurt out his theory in front of the man. But no, he had to play his hand because oh, he was so clever, wasn't he?

His own damn fault, all of it.

And the next girl? Blonde hair and innocent, unseeing eyes? That's all on him.

Rick looks up at the sound of footsteps. It's Kate, of course, but she's not looking at him that way – not looking at him at all actually – and maybe she's realised he's to blame.

He's sure that he deserves her scorn, but she just settles next to him in silence.

She sits close enough that their knees brush, and then she slides closer still, until she's pressing against him, thigh to thigh, calf to calf, and he feels some of the tension in his shoulders ease.

"Here you go."

Rick takes the cup she offers but he doesn't drink from it. "Thanks."

Kate hums in her throat. "Tell me something, Castle. Why did he let you live?"

It's obvious, isn't it?

"To punish me. To make me pay for ruining his plan. Now he's going to kill again, all because I couldn't stop him. And I feel so…"

Impotent. Stupid. Angry. Worthless.

All of that and more.

He doesn't have the words for it, can't think of a way to summarise the bubble of anger and worry and acid churning in his gut, and that makes it worse, of course, because he's a wordsmith and it's supposed to be what he does best.

A hand settles on his knee, understanding and warm. "I know the feeling."

It's my fault, he wants to say. I did this, but when he looks at her there's no accusation in her eyes, no heat or fire or anger. She doesn't blame him and he doesn't understand why not, exactly, but Rick wraps his own hand around hers, squeezes tight, and lets her simple truth anchor him. "I know you do."

Kate's face twists into a frown, unnatural in the blue light reflected off the pool. The shadows highlight the angle of her cheekbones, the depth of her eyes, and her face is strange and familiar to him all at once.

He leans towards her, feels the puff of her breath against his cheek, and lets her draw him back from his own thoughts.

She's looking at their hands, he realises, when his eyes follow hers. They're still clasped together, but his sleeve has rolled up, and there are angry marks burnt red on his wrists.

"He could have killed you, Castle."

"But he didn't."

"I thought I was going to find a body."

"I'm fine, Beckett."

Kate bumps her shoulder against his arm and turns her face back to the pool. "I'm glad," she says.

It's the second time she's said as much and he squeezes her hand because he doesn't know how else to respond.

They sit together then, silent, until well after the cup in his hand has lost its warmth. He concentrates on the shoulder pressed against his side, the fingers trapped between his own and, eventually, the tension bleeds out of him until he can breathe without the twist of guilt at the base of his spine.

"Come on," she says, and she pulls him to stand. "No point hanging around here all night."

He misses the warmth as soon as she's moved away and so he follows her as she makes her way back through the parking lot. He's surprised when he finds only a few uniforms left milling about the motel.

"Boys gone already?"

Kate nods. "Yeah, the paramedics dragged Ryan to the hospital and Espo only stayed long enough to secure the scene."

"Leads?" He tries not to wince at how hopeful his voice sounds.

"A few," she hedges. "C'mon."

Rick pauses as they reach her car. "Back to the precinct?"

"No." There's a sigh waiting to escape her throat. "We'll catch him, Castle. We will. But not tonight."

Rick can only nod in response because no, they won't, he knows, not before he kills again, and maybe not even then.

"Home?" she asks when he slides into the passenger seat.

Rick knows what he should say – yes, home and thanks for the rescue, Beckett followed possibly by an I'll see you tomorrow – because he has a mother and a daughter and a girlfriend who are, mostly likely, waiting for him. He should want to see them – and he does – he just can't find the energy for their questions and their worry.

He's used to being the centre of attention and if he's honest, he enjoys it, mostly, but he needs to find the eye of the storm first. His head is still in a dark place and he needs a bit more calm, a fraction more of this brand of quiet understanding before he can smile at his kid and lie about being in any danger.

"I'd rather not just yet," he says, and he doesn't miss the way his partner's face changes. It's subtle, but the wrinkle in her brow eases, just a little, and she's maybe a little bit relieved, he thinks.

"Okay." Kate rests her hand over his arm. Her fingers graze the marks on his wrist. "My place, then."

TBC...

Note: I decided to stop this chapter here because it was getting a little long. The next bit is written, though, and will be up in a few days.