Attempting to return to UNIT HQ, the Doctor (Tom Baker) and Sarah land in England in 1911, where an ancient force is preparing to return and wreak destruction on the Universe. Sutekh the Destroyer, last of the Osirans, is planning to free himself from his prison on Mars. His robot Mummies are building a rocket to destroy the device which holds him prisoner and If he isn't stopped, there is not a force in the Universe which can stand against him.

Espionage thriller, based on the 1959 ITV series, starring Stanley Baker, Peter Cushing and Mai Zetterling. Joe Newman (Baker), a jazz musician who has lived in England since the outbreak of World War II, is greatly surprised to discover that his father, believed to have died some 20 years before, may still be alive and heads to his hometown in Bavaria to investigate. While there he becomes enveloped in a conspiracy that reaches to both sides of the Iron Curtain and involves the mysterious Dr. von Brecht (Cushing).