3x24 Knockout

Richard Castle: "Continue mission"? If Lockwood isn't going after the third cop, then who's the mission?
Captain Roy Montgomery: I put a protective detail on her. Plainclothes. These guys are good.
Richard Castle: Good enough to stop Lockwood? She's not gonna stop. And the next time he sees her, one of them is gonna die. Take her off the case.
Captain Roy Montgomery: Castle, did Beckett ever tell you how we met?
Richard Castle: No.
Captain Roy Montgomery: I was working late one night, went down to archives to locate some old reports, and there she was with a flashlight and a Bankers box open on her lap, studying this unsolved. She was a patrol cop then, she wasn't even authorized to be down there. When I asked her what the hell she was doing, she told me this was her mother's case. And she'd found some things that didn't add up. Now, I could have written her up, right then.
Richard Castle: Why didn't you?
Captain Roy Montgomery: Because I knew it wouldn't stop her. It was there in her eyes, man. And I thought "With this kid's tenacity and some training, I mean, she'd make a hell of a Homicide."
Richard Castle: That tenacity's gonna get her killed.
Captain Roy Montgomery: I cannot make Beckett stand down, Castle. I never could. And the way I figure, the only one who can... is you.

Kate Beckett: Roy, I am over it. I mean it, I want him gone.
Captain Roy Montgomery: Okay, he's gone.
Kate Beckett: What?
Captain Roy Montgomery: You want Castle gone, he's gone.
Kate Beckett: I... what about the mayor?
Captain Roy Montgomery: [laughs] This is my house, Kate. The mayor doesn't call the shots here, I do. You ought to know that by now.
Kate Beckett: But, I...
Captain Roy Montgomery: I could've kicked Castle to the curb years ago, any time I wanted to. The only reason I kept him around this long was 'cause I saw how good he was for you. Kate, you're the best that I've ever trained, maybe the best I've ever seen. But you weren't having any fun before he came along. We speak for the dead. That's the job. We are all they've got once the wicked rob them of their voices. We owe them that. But we don't owe them our lives.
Kate Beckett: He said that we can't win this.
Captain Roy Montgomery: He's right. I've spent most of my life walking behind this badge, and I can tell you this for a fact... there are no victories, there's only the battle. And the best that you could hope for is that you find some place where you can make your stand. If this is your spot, I will stand with you.

Richard Castle: Lockwood kills Raglan, then he shanks McCallister, both of them ex-cops who had something to do with your mother's murder. He's cutting off all avenues of your investigation
Kate Beckett: Castle, he's not cutting them off. He's giving me new ones. I've been going to that prison every week for the last four months to have a staring contest with the Devil, and the Devil just blinked.