DOCTOR: Something's wrong. Something's very wrong. Oh no, has it come to that? Regenerate, yet unregenerate. Oh, alas, poor Peri. Not for us the pleasures of Vesta Ninety Five.

PERI: What are you saying?

DOCTOR: I am a living peril to the universe. If this poor hive is to be cleansed, there's only one recourse. Contemplation. Self-abnegation in some hellish wilderness. Ten days, ten years, a thousand years! Of what consequence is time to me? I shall become a hermit, and you, child, shall be my disciple. I know the very place. An asteroid so desolate. Titan Three is where I shall repent!