RUBY: Can't we use the TARDIS and go find him?

DOCTOR: There are as many dimensions as there are atoms in the universe. Don't even know his real name.

RUBY: I'm sorry.

DOCTOR: Anyway. It is what it is, so onwards. Fine. Next. Off we go. Where shall we go? Anywhere.

RUBY: Doctor, you don't have to be like this.

DOCTOR: I have to be like this, 'cos this is what I'm like. Onwards. Upwards. New horizons. Moving on. It's fine.

RUBY: Okay, can you just shut up a second?

(She gives him a hug.)

DOCTOR: It's good to have you back, Ruby.

RUBY: And you, Doctor. Hmm.