Clara started out like Sophia but ended up more like you.

Castle: I thought you were the bad guy?
Gage: If I were the bad guy, you would be dead by now.

Castle: How did you get here?
Sophia: I'm CIA.

Beckett: So you slept with her?
Castle: Yea, yeah I slept with her.
Beckett: Have there been others? Muses?
Castle: No.
Beckett: Just wanted to see how big the club was.

That whole sinking car thing is much cooler in movies than in real life.

I guess the good thing about having your daughter at crime scenes is that she can bring you dry clothes.

Life is a journey

Castle: I found something.
Beckett: Shouldn't you tell Sophia about it?
Castle: She's not my partner. You are.

Castle: We're all on the same team here.
Beckett: No we're not. You're on her team because the way you look at her, you're sure as hell not on mine.

Beckett: What are you doing?
Castle: Bracing myself to shield you from a hail of bullets.

If I did tell you, I'd have to kill you.

It was never like it is with you and me.

Castle Quotes

Sometimes the hardest things in life are the things most worth doing.

Castle

Castle: How do you know when you're in love?
Beckett: All the songs make sense.