(Priyanka, Clara, and the Doctor enter the TARDIS.)

PRIYANKA: I sneaked in here as a kid when no one was looking. Their own fault – they kept telling me not to go near it. I thought you were a dream, Doctor. But Dad said no, you might be unbelievable, but you were real. You were a hero to him, I think. He always said you'd be there if he needed you...

DOCTOR: Bit wide of the mark, then, wasn't he? To hell with heroes! All they do is make you believe in them, then let you down.