Castle, Season 5

[Beckett meets Castle at a swing set in a park]

Beckett:
I'm sorry...I shouldn't have kept secrets.

Castle:
It's who you are. You don't let people in. I've had to scratch and claw for every inch--

Beckett:
Castle--

Castle:
Please let me finish. I've been doing a lot of thinking about us, about our relationship. What we have. Where we're headed. I've decided I want more. We both deserve more.

Beckett:
I agree.

Castle:
So whatever happens...whatever you decide...[Castle gets off the swing and kneels in front of Beckett] Katherine Houghton Beckett...[he pulls out an engagement ring and holds it up] will you marry me?

[Fade to black--end of episode, end of season]