Back stabbing, adultery and betrayal. That is why I hate politics.

Rick Castle: I know I have occasionally theorized that a conspiracy was afoot.
Kate Beckett: Occasionally?

Kate Beckett: You texted Castle and not me?
Kevin Ryan: Well, when you have a crazy theory you don't call the voice of reason.

It happened on his watch so for Ryan it means it's all on him until he finds this guy.

Rick Castle: Checking you for bites and scratches. Just making sure you didn’t somehow get impregnated.
Kate Beckett: If you think that’s how I’d get pregnant we need to talk.

Kate Beckett: Wait, you signed up to go to Mars. When?
Rick Castle: A couple years ago.
Kate Beckett: Where was I?
Rick Castle: We were fighting.

Kate Beckett: Four adults together in one space, we're bound to step on each other's toes.
Rick Castle: Yeah, well there were a lot more toes than usual tonight.

Castle we have a murder. To solve not to commit.

Kate Beckett: Thanks for coming to get me.
Rick Castle: Always.

Rick Castle: I don't know how you did it.
Kate Beckett: What?
Rick Castle: Kept it together the two months I was missing. Two days I didn't know where you were and it nearly killed me.

She’s as shrewd and high functioning of a sociopath as he ever was.

Kate Beckett: Castle, stop chasing the mice in your head.
Rick Castle: What if they're leading me to the truth?

Castle Quotes

Oh, absolutely not! You will not and do you know why? Because you're a fighter. What have you always told me? No one will give you anything in this life. You must earn it and look at you. Almost 20 years later and you're back on Broadway. You have earned this.

Rick Castle

To bravery, to commitment, to love, to sacrifice.

Ryan