Carrington is holding the astronauts at a secret location but when he takes the Doctor, Liz and the Brigadier there they find they have been kidnapped.
Quest roles:
Nicholas Courtney(Brig. Lethbridge-Stewart), Cyril Shaps(Archimandrite), John Abineri(Ranquin), Ronald Allen(Ralph Cornish), Ric Felgate(Astronaut), Dallas Cavell(Quinlan), Gordon Sterne(Heldorf), Steve Peters(Astronaut), William Dysart(Reegan), Neville Simons(Astronaut)