Two schoolboy musicians help to catch a jewel thief

Rogues Jelly Knight, Scapa Flood, and Lennie the Dip leave prison expecting boss The Duke to have their stash ready to share out. Instead, Duke's girl Sara gives them the news Duke is dead and the money gone on nursing care. They soon discover that Duke is actually running Hope Springs Nature Clinic with the help of most of the local villains. Very strange - and the nearby army camp and Sara's encouragement of Lieutenant Vine would seem to be no coincidence either. Written by Jeremy Perkins

An alien distress call draws the Doctor and Peri to Earth, 1985, where they uncover a Cyberman plot to change the course of history.