DOCTOR: I believe, I believe I haven't seen everything, I don't know. It's funny, isn't it? The things you make up. The rules. If that thing had said it came from beyond the universe, I'd believe it, but before the universe? Impossible. Doesn't fit my rule. Still, that's why I keep travelling. To be proved wrong. Thank you, Ida.

IDA: Don't go!

DOCTOR: If they get back in touch, if you talk to Rose, just tell her. Tell her. Oh, she knows.