Castle, Season 6

Beckett:
There's not a shred of evidence that Tyson is alive, let alone involved in this.

Castle:
Tyson doesn't leave evidence, not unless he wants us to find it. Like that deleted photo. No evidence, plus meticulous planning, that's vintage 3XK. And this case has it in spades.

Beckett:
Castle-

Castle:
And you wanna know some other 3XK classics? Using people that look like other people. Using a killer to act on his behalf. Beckett, how can you not see it?

Beckett:
What I see is the guilt that you feel.

Castle:
This isn't about me.

Beckett:
Look, when Tyson escaped, he outsmarted all of us. But you've always blamed yourself.

Castle:
[Nearly yelling] Because I'm to blame. [Calmer voice] It's him. It's Jerry Tyson.

Beckett:
Don't chase ghosts, Castle, okay? It's not worth it, trust me.