Adventure, Drama, Science Fiction | 15 May 1971

Jon Pertwee, Katy Manning, Nicholas Courtney

When the Master steals the Time Lords' secret file on the Doomsday Weapon, they grant the Doctor a temporary reprieve from his exile on Earth to deal with the crisis. He and Jo arrive on the planet Uxarieus and become enmeshed in a struggle between an agrarian colony and a powerful mining corporation.