On a holiday in Paris, the Doctor (Tom Baker) and Romana uncover a plot to steal the Mona Lisa. Julian Glover. Duggan: Tom Chadbon. Countess: Catherine Schell. Kerensky: David Graham.

The TARDIS arrives on the space liner Empress which has become locked together with a private ship, the Hecate, after colliding with it on emerging from hyperspace. The Doctor and Romana meet the scientist Tryst, who has with him a Continuous Event Transmuter (CET) machine containing crystals on which are stored supposed recordings of planets that he and his team have visited.

Arriving in London at the end of the 19th Century, the Doctor and Leela meet a police pathologist investigating a series of murders, which leads them to an ancient Chinese god living in the sewers.

In their search for the Key to Time, the Doctor and Romana land on a strange planet. Captain: Bruce Purchase. Romana: Mary Tamm. Mentiad: Bernard Finch. Pralix: David Sibley.

The Doctor is shot at by two men from a methane refinery on the third moon of Delta Magna.

The TARDIS arrives on a planet where a savage tribe called the Sevateem worship a god called Xoanon. The Doctor discovers that Xoanon is in fact a spaceship computer that he tried to repair at some point in his past and inadvertently drove mad by giving it a multiple personality.

Arriving in London at the end of the 19th Century, the Doctor and Leela make friends with a police pathologist, Professor Litefoot, and learn that hairs taken from the clothing of a dead body found floating in the Thames seem to have originated from a very large rat.

Dr. Who and Romana visit the "Leisure Hive," a decaying resort on Argolis, where a coup d'etat is imminent. Tom Baker, Lalla Ward. Vargos: Martin Fisk. Pangol: David Haig. Mena: Adrienne Corri. Stimson: David Allister. Foamasi: Andrew Lane.

Dr. Who battles a mind machine that contains an evil alien parasite. The Master: Roger Delgado.

Dr. Who battles a mind machine that contains an evil alien parasite. The Master: Roger Delgado.

The Doctor is forced to land on Karfel, where the evil Borad plots to replace the inhabitants with a mutated life form. Peri: Nicola Bryant. Borad: Robert Ashby. Tekker: Paul Darrow. Vena: Jeananne Crowley.

A race of mutants, doomed to endless degeneration, forces the Doctor to help them. Peter Davison. Black Guardian: Valentine Dyall. Mawdryn: David Collings. Nyssa: Sarah Sutton.

The newly regenerated Doctor and Amy Pond must save the world in less than 20 minutes from galactic policemen known as the Atraxi.

The Doctor and Amy travel to Britain of the future, where people live in a giant spaceship; Amy comes across the terrifying Smilers.

The Doctor and Amy meet Winston Churchill during a trip back to World War II, where they also encounter the Daleks.

Part 1. The Doctor hunts the last of the Weeping Angels through the Maze of the Dead; the mysterious River Song is back in the Doctor's life, but he doesn't know if he can trust her.

Part 2. The Doctor and his friends are forced to escape through the forest vault after they are surrounded by the Weeping Angels.

The Doctor suspects something isn't quite right with the daughters of the family that protects the streets of Venice.

The Doctor returns to Amy on the night before her first child is born.

Part 1. Scientists discover something isn't right beneath Earth's crust while drilling.

Part 2. Scientists discover something isn't right beneath Earth's crust while drilling.

Amy battles an alien in France with Vincent Van Gogh.

The Doctor investigates a mysterious staircase in a building where people can go up, but never down.

Part 1. A message on a cliff; a puzzle box that opens from the inside; the fates draw closer for the TARDIS.