Carrington is planning to expose the aliens on live television and call for an interplanetary war and the Brigadier must rescue the Doctor and Liz in time to stop him.
Quest roles:
Nicholas Courtney(Brig. Lethbridge-Stewart), Terry Walsh(Doran (uncredited)), John Levene(Sergeant Benton), John Abineri(Ranquin), Ronald Allen(Ralph Cornish), Peter Halliday(Soldier), Michael Wisher(Magrik), Ric Felgate(Astronaut), Steve Peters(Astronaut), Joanna Ross(Control Room Assistant), Peter Noel Cook(Alien Space Captain), Geoffrey Beevers(Melkur (voice)), William Dysart(Reegan), Neville Simons(Astronaut)