SARAH: Ah, this isn't Cassiopeia.

DOCTOR: It's Antarctica.

SARAH: We're back where we started!

DOCTOR: Yes.

SARAH: We won't get a suntan here.

DOCTOR: No.

SARAH: You forgot to cancel the coordinate programme, didn't you.

DOCTOR: Yes.

SARAH: Shall we try again?

DOCTOR: Yes. Just a minute.

SARAH: What?

DOCTOR: Have we been here before, or

BOTH: Are we yet to come?