Polly is taken prisoner by the rebels who intend to use the Daleks to take control of the Earth colony. The Doctor discovers that all three Daleks have now been reactivated.

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.

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.

The TARDIS arrives in the marshes of the third moon of the planet Delta Magna. While trying to get an accurate reading on the tracer, the Doctor is shot at by Thawn and Fenner, two men from a nearby methane refinery.

Conclusion. The Doctor intervenes in the plans of a nefarious marshal who plans to wipe out the indigenous inhabitants of a colony planet.

Capt. Jack storms back into the Doctor's life; the Tardis travels to the end of the universe.

Part 1. Harry Saxon becomes Prime Minister, but has dark ambitions.

Part 2. With The Doctor imprisoned by The Master, Martha endeavors to save the world.

Kylie Minogue joins Doctor Who to play Astrid, a waitress on a doomed spaceship that eerily resembles the Titanic. When a meteor hits, Astrid and The Doctor must protect the survivors from and prevent the whole ship from crashing to Earth.

Donna is determined to find the Doctor, even if it means braving Miss Foster and her hordes of Adipose.

The Doctor and Donna visit Pompeii in AD 79, on the eve of the eruption of Mount Vesuvius.

The Doctor takes Donna to her first alien world, but the Ood-Sphere reveals some terrible truths about the human race.

Part 1. Sontaran warriors set their sights on the Earth and its inhabitants.

Part 2. As poison gas suffocates the Earth's population, the Doctor and UNIT team members work to eliminate the threat.

The Doctor meets the most important woman of his life.

Part 1. The Doctor and Donna must uncover the truth behind the Nodes and the Data Ghost to uncover the library's secret.

Part 2 . As the shadows rise, the Doctor forges an alliance with the mysterious River Song.

The overlap between quantum reality and science fiction is discussed.