Ryan: [Looking at a cardboard cut-out of Castle] He really is ruggedly handsome.

Simmons: You painted since the last time i was here. You'd have been about 16 wrestling some pimply kid in the back of his daddy's wagon. Wondering if you were gonna give it to him or not.
Castle: Hey that's enough!
Simmons: He's sweet on you. Makes him brave.

[Castle walks into the station carrying two coffees. Natalie is writing on the "murder board", Beckett eyes at her uneasily]
Natalie: [Takes a coffee] Thanks, Castle!
Castle: [Stunned at her audacity] Tha--that's, I was-- uh... you're welcome?
[Beckett looks shocked and distraught]
Castle: So, where are we?
Natalie: Ryan and Esposito are digging into Tanya Wellington.
Castle: [Directly addressing Beckett] Mmm, what about Duke Jones? Did his neighbour confirm his romantic evening?
Beckett: He--
Natalie: [Cuts her off] So did a couple of other neighbours, who complained about the noise. So it looks like Duke Jones allibis out.
Beckett: [Put out] What she said. [To Castle] Can we talk for a second?
Castle: Sure.
[Beckett loops her arm through his and quickly leaves the room, ending up frantically dragging him into another room]
Beckett: She took my coffee, Castle!
Castle: It's just coffee.
Beckett: Then what's next? My soul?! Everything I do, she does. Even when I'm thinking I can feel her in my head like some kind of a brain-eating parasite from one of her movies!

[Natalie walks in dressed up as Beckett, with a brunette wig and similar suit. Castle's and Beckett's jaws drop.]
Castle: Just like I dreamed it! [They both stare at him] Did I say that out-loud?

[A captured suspect begins chewing on something]
Castle: Cyanide capsule! [pries the object from the suspect's mouth, inspects it with a flashlight, sees it's chewing gum] ...Ew!

[After entering a sewer discovered next to a basement.]
Beckett: This must be part of the old sewer system.
Castle: Probably the exact sewer system --- This is incredible, isn't it?
Beckett: Yeah! Aside from the fact that it's damp, cramped, dark, and we're almost certainly walking in rat poop. [high pitched] Awesome.

[Castle and Beckett had been captured, interrogated and injected by government agents the night before]
Beckett: Those men knew who killed Marie and they refused to tell us.
Castle: They also refused to confirm that J. Edgar Hoover liked to wear dresses.
Esposito: [walking up and checking out the injection marks on their necks] Abducted by government agents, huh? [grins] Come on. What were you two really doing?
Beckett: [rolls eyes] It's not a hickey, Esposito.
Esposito: You both have one.
Castle: I wish it was a hickey. [Beckett looks up with a small smile] It's from the injectors.
Esposito: Is that what the kids are calling it these days?
Castle: They were Men in Black!
...
[Ryan walks up to Castle, Beckett and Esposito]
Ryan: Hey. Are those hickeys?
Esposito: Yes.
Beckett: No.
Castle: I wish.