Audio problem: If you listen carefully to the soundtrack of part four of "The Moonbase", some 'chatter' and 'feedback' from the floor manager's headphones can be heard. (At the time this particular episode was recorded, there was just a one-week gap between recording 'Doctor Who' and transmission, so there was no time available to re-record the episode, and this mistake had to be left in).

Revealing: The doors and walls wobble badly as Jamie and Ben barricade the entrance to the medical unit.