How am I supposed to be in a relationship with her if she won't let me in?

Beckett: Why is it so important to you that I believe all this stuff about fates, psychics, and Santa Claus?
Castle: Because, if you don't even believe in the possibility of magic, you will never ever find it.

Dude, where's your car?

I can't believe you're letting you're ex wife stay with you...with us.

Beckett

Castle: I am not saying I can speak with the dead, just that there are people in the world more sensitive than me.
Beckett: Now that's not hard to believe.
Castle: Walked right into that one.
Ryan: uh huh.

My partner's daughter is missing and you're in my way!

Beckett

I don't get it. He's into you and your determined not to give into these feelings that you clearly have for him. So he fantasizes about you through his writing. It is literally verbal masturbation.

Natalie

You would make a terrible conjoined twin.

Castle (to Beckett)

I don't want to let fear win.

Alexis

That's like throwing gasoline on fireworks.

Esposito

My loft is overrun with red heads.

Kate: What am I going to do, just sleep in every morning and screw around till the phone rings? What kind of life is that?
Castle: Mine.

Castle Quotes

I need time to stop being mad and you need time to figure out a way to be OK with this.

Alexis

I tried to stay in the car I really did.

Castle