THE FIFTH DOCTOR His youthful appearance belied his wisdom and experience, but this Doctor still found it frustrating that so many people questioned his judgement, especially his companions. While on an alien planet he and his companion Peri contracted a disease and the Doctor gave Peri the only cure, necessitating another regenerationï¿½?ï¿½ THE MASTER from ï¿½??PLANET OF FIREï¿½?TM The Fifth Doctor and Turlough are on the island of Lanzarote because the TARDIS has detected a mysterious signal being transmitted from an unknown, recently salvaged artifact. They meet a young American botany student named Peri Brown, whose stepfather has been replaced with a shape changing robot as part of a plot by the Master. He plans to bring the TARDIS to the planet Sarn, so he can use that world's revitalising Numismaton gas to restore his body, accidentally shrunken in an accident. The Master is apparently defeated when the stream of gas turns to a normal hot flame. The Doctor destroys the shape changing robot, Kamelion, at the robot's own bidding as it has become completely unstable. Turlough leaves to return home, while Peri leaves with the Doctor.