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.

• BBC
• Jon Pertwee
• Katy Manning
• Nicholas Courtney
• Roger Delgado
• Nicholas Pennell
• John Ringham
• David Webb
• Sheila Grant