Author's Note-This story popped into my head and forced all my other stories out until it was written, so I thought it best to write it down. Each chapter is stupidly short. Most are under a page long, the shortest one so far not even hitting 300 words, but it's how it came to me. I hope you enjoy it. I've written the vast majority of it already so posting should be quick and painless. Oh, one more thing. One of the most frequent complaints I get is my dialogue tags. Here's the thing, the way I write is the way I've been writing forever. I like the way I write. But I understand that some people find it confusing and I'll try to make it less so. But I'm aware of it okay? Okay. Read, review, enjoy NYLF xx

Castle watched from the break room while he was making them both coffee. Kate was smiling, properly smiling, all teeth and sparkly eyes, as she listened to whatever was going on on the other end of the phone. In the two years he'd been working with her, he didn't think he'd ever seen her so happy.

She'd once told him that there were many layers to the 'Beckett-Onion' but the only one he was itching to peel was the one she kept closest to the vest.

For a cop, the lead detective in the team no less, she worked amazingly regular hours. She always left at five, on the dot, without fail. Sure, the odd occasion where they were working a lead, or on stake out, or undercover, she'd stay longer, but she'd always excuse herself first. Both Ryan and Esposito would nod, both looking far more in the know than he was, and then she'd disappear for five or ten minutes. When she came back there was absolutely no indication where she'd been and she ignored him when he asked. By the third or fourth month of working with her, he'd stopped asking.

Kate hung up the phone and schooled her features back into her professional impassive mask, just as Castle made his way back over, coffees in hand. She nodded in thanks before getting back to the file in front of her.

There was something there, he could feel it. The boys knew, and he'd bet his bottom dollar that the Captain did to, given the nod he always gave her when she left every night.

He knew about her mother, the ex boyfriend that left her for his job, the alcoholic father. He knew things about her many others didn't. He just didn't know why she felt she couldn't trust him with what must be one of the biggest secrets she had, given how closely she was guarding it.

He would find out, but it would take time and patience.

He didn't want to know for Nikki, this wasn't a book thing. This was a Beckett thing. He wanted to know, because he wanted to know her. Really know her. In a 'I'm going to make you my wife and grow old with you' kind of way.

"Castle? You with us?" Right, she was talking. Castle shifted his eyes from his cup and looked up at her.

"Yeah, I'm here." Kate gave him an odd look before nodding and turning to say something to the boys.

He would find out even if he had to wait forever. He wanted to know about her life outside these walls but he'd never disrespect her enough to be underhanded about it. He'd learnt his lesson with her mom and never wanted her to feel like she couldn't trust him. He'd just have to prove he could be there for her and that he was a good enough friend, that she could tell him her greatest secret.