It's time...

The Doctor: Amy Pond. The girl who waited. You waited long enough.
Amy Pond: When I was a kid, you said there was a swimming pool. And a library, and the swimming pool was in the library.
The Doctor: Yeah, not sure where it's got to now. It'll turn up. So, coming?
Amy Pond: No.
The Doctor: You wanted to come 14 years ago.
Amy Pond: I grew up.
The Doctor: Don't worry. I'll soon fix that.

From Doctor Who, Series 5, Episode 1: The Eleventh Hour. This was also the source of Monday's teaser.