A/N: Thank you to Lou for the wonderful prompt: "What if Undead Again really was his last case and the next time he sees her she's there to arrest him in Probable Cause (5x05)." I took some liberties with it and also apologize for taking so long so fill it! There will be more chapters to this; I hope you enjoy!

And I'll use you as focal point
So I don't lose sight of what I want
And I've moved further than I thought I could
But I miss you more than I thought I would

- "I Found", by Amber Run

It's been months since they've talked to one another, since she's seen him. He's been radio silent since the zombie case. He'd told her it would be their last case but part of her had hoped he'd be back, that he wouldn't disappear from her life altogether, that he'd contact her in some way.

He hasn't.

She doesn't understand what happened between them; why he reverted back to his old ways and dove back to meaningless dating and presumably shallow relationships. The memory of a petite, blond flight attendant sets her stomach askew and her insides cringe. She can't deny that she's missed him, that she's thought of him nearly every morning when she gets her own coffee and every night after her shift ends when she returns home to her cold and lonely apartment.

But she won't beg. He's let her go, made it clear that he is done waiting while she'd painstakingly ascended the rocky slopes of recovery. His departure has laced her veins with betrayal and she refuses to grovel at his feet.

If he could move on so could she.

Except she hasn't. She's been miserable. So much so that she couldn't even deny it when Lanie had shown up at her place a couple of nights ago. Richard Castle has left a gaping hole in her chest and although it's been months, the void has yet to be filled and the ache that sets her heart on fire is still very much present, a fire that refuses to be quelled to embers.

And now his fingerprints have been found on the scene, as identified by the CSU report and her hands are shaking with it, with the realization that she's about to see him again. The boys have gone to pick him up to bring him in for questioning but she hates that after months apart, this is how they'll find each other. It has Kate's stomach churning with the sick sense of déjà-vu, the situation resembling one two years prior after a summer spent alone. He'd never called after having returned from the Hamptons with his ex-wife in the fall and she'd found him with a gun standing over a dead body.

This is all too familiar. She needs a moment to regroup. To make sure she doesn't lose it when she enters the box to once again interview Richard Castle for murder.

But dammit, he hurt her. She doesn't know how to move past that or focus on anything other than what has been left unsaid between them.

She doesn't see him when he arrives at the precinct. Kate leaves the women's restroom and she notices Esposito waiting at her desk. His back straightens when he notices her approaching.

"Castle's in interrogation one."

"Has he said anything?" She asks, her voice devoid of emotion. She is treating him like any other suspect. She can work this case like any other.

"Only that he's innocent and has no idea what this is about. He claims he doesn't know Tessa and has never been to her apartment," Espo tells her and she sighs, closing her eyes. She doesn't believe Castle is behind this. He writes about murder for a living but this… This is just sick.

Still, she needs to follow protocol and interrogate him.

"Are you sure you don't want me and Ryan to take care of this?" Espo asks her.

"I'm fine," she assures him and shoots a glare his way for good measure. She doesn't need her partners thinking she can't handle this.

She appreciates the big brother act but she's a big girl. She can interrogate the man who left three months ago and took her heart with him.

She can.

Kate heads towards Interrogation One. When she opens the door, the look on Castle's face is something akin to longing but it disappears after a few seconds, replaced by the cold indifference she was treated to in the weeks prior to his leaving.

"Beckett," he greets her, meeting her eyes but they hold nothing, no warmth, no joy or shimmer as she'd hoped and it has her chest aching.

"Castle," she responds cordially. Nothing like she's allowed herself to hope, nothing like the way he greeted her every morning with a smile as warm as her coffee.

Focus, Kate.

"Your fingerprints were found at our crime scene this morning. Our victim's name was Tessa Horton, do you recognize her?" She asks him as she sets a photo of Tessa down on the table in front of him. He's looking at her like he's trying to figure her out, with something like accusation in his eyes, and she won't be the one to break eye contact, she needs to hold the power in this room but fuck if this isn't already shredding her to pieces. His jaw tenses and he finally looks down at the picture.

She gulps in as much air as she can because she doesn't know when she'll get the opportunity to breathe again. Why can't she breathe when he looks at her like that?

"I don't know her. And I have no idea how my fingerprints got to your crime scene," Castle answers her and looks at her again, waiting for her next move.

"Really? Because her roommate said she'd been dating a mystery man she described as rich, handsome and generous. Seems to me, you fit that bill, and your semi-famous status would be reason enough to keep your relationship a secret," she explains and his eyebrows hitch.

"I'm flattered, Detective. But like I said, I didn't know her," he repeats and she can see the irritation on his face, how his jaw is set tight, his brow furrowed. She's missing something here. "If you must know, I haven't been involved in any romantic relationships recently."

Her heart skips and she hates herself for it. He could be playing her. Except she knows he's not, he's telling her this not for the benefit of their investigation but for her personal knowledge. Why is he doing this? He is the one who left and gave up on her, on them. She glares at him, doesn't have anything else to add if she is to stay stoic and professional with him. She won't let him gain the upper hand.

"So where were you last night, Castle?" She asks, ignoring his last comment.

He scrubs his face with one hand and sighs. When he looks back up at her, his face is somber, "I was at home alone, writing. Or trying to anyway." He looks at her, his eyes sincere and honest. Shit, this would be a whole lot easier if he had an alibi.

She doesn't respond. He knows what this means and how it looks. They look at each other and for a second she feels like they are back; like he is back. Like he's here at the precinct as her partner and they are about to go out there and build theory together. Except he's on the wrong side of the table and she's about to have to put him in holding. Every fiber of her body is telling her he's innocent but a small voice in her head keeps repeating that she thought she knew this man.

She doesn't. He left her before they had a chance to begin. She really thought they'd make it.

"We are going to have to hold you." She informs him, about to turn away when she feels his fingers grab hold of her hand and her entire body seizes, the synapses in her hand and fingers firing intensely because this is the first physical contact they've had in months and apparently she hadn't known how much she's craved it. It's something she's never known, his touch. Something that isn't hers to miss because it was never hers to begin with, save for the few instances when they allowed their fingertips to brush at the exchange of coffee in the morning. But she always thought she'd someday find out what it was like to be held within the haven of his arms and comforted by the span of his hands at her back. She'd found herself yearning for it in the weeks of her suspension, her body aching for something it's never had.

And at the touch of a hand it all comes rushing back to her, a wave of heavy emotion hitting her directly in the chest and she has to stop herself from running her thumb along his knuckles. He doesn't stop himself however and he does just that, dusting his thumb over the back of her hand reminding her of a moment shared between them and a golden retriever in her apartment. Her eyes fall shut and she knows she's showing her hand, her heart, but god, she could have sworn they were headed somewhere five months ago.

Kate inhales and opens her eyes. She can't let herself drown in their sea of missed opportunities. He closed that door when he left for good. She finds his eyes heavy with remorse and she knows is about them, not about this case and he has no right to do this to her. Not when he left.

"Kate."

The sound of her name on his lips breaks the spell and she removes her hand from his, regains the little composure she can and straightens from the table. She grabs the files and heads for the door.

"You really believe I'm capable of doing something like this?" He asks her as her hand reaches for the handle on the door. She looks back at him and he looks hurt, betrayed, almost.

In this moment, she hates herself a little for not reaching out to him. For not talking it through and demanding that he stay, or at least give her an explanation for his leaving. If she had, maybe they wouldn't find themselves in this predicament. If she had, maybe by now she'd know how it feels like to be comforted by his touch.

Maybe he isn't the only one to blame for the hurt she's suffered over these last few months. She let him leave.

Why did she ever let him leave?

And then she remembers he asked her a question and, no, she truly does not believe he could do something as horrifying as this. But she can't tell him that.

"I have to follow the evidence wherever it leads."

And with that she leaves the interrogation room. Why is it that she still can't breathe?