Synopsis: Having successfully repaired the TARDIS, the Doctor journeys into space and lands on a starship manned only by robots and carrying a cargo of unconscious people. Awakening a girl called Trandi, the Doctor discovers that her people, the Crallicans, have been enticed away from their dying world by the evil Vogans. Taking Trandi in the TARDIS to the starship's destination, the Doctor discovers that the Vogans intend to use the Crallicans as slave labour to mine the Voganite minerals which they depend on. In a pretence of cooperation, the Doctor agrees to shuttle the slave from the ship to the planet's surface in the TARDIS. However, as soon as the operation is complete, the Vogans intend to destroy the Doctor and the TARDIS with a bomb.
Synopsis: John and Gillian meet their grandfather, "Doctor Who". Together they travel to thirtieth century were they meet the peaceful Thains. The Thains are being attacked by the evil Kleptons in their flying machines and by their destructive creeper plants.