RICK: You say you’re the doctor? So do you mean you’re, like, the new doctor?

DOCTOR: Interesting question. I suppose that all depends, doesn’t it?

SCOTT: On what?

DOCTOR: On when you meet me. I mean, if you meet me in your past and my future, I’d be the new Doctor to you, but the old Doctor to me, whereas if you meet the old me in your future, I’d be the new Doctor now and the old Doctor later. You see?

SCOTT: Huh?

DOCTOR: You haven’t met the future me by any chance, have you?

SCOTT: Er...no.

DOCTOR: Aw, pity. I wanted to know whether I was ginger.