Arriving on the barren world of Androzani Minor, the Doctor and Peri find themselves embroiled in a long running, literal underground war. At the heart of the conflict is a substance called Spectrox - both valuable and deadly! The Doctor & Peri wind up being poisoned by the material, which is killing them slowly and painfully unless they can find a cure. As the conflict heats up and the situation gets more desperate, the Doctor realises time is running out - both for Peri and himself...

When the TARDIS is in need of repairs, the Doctor and Peri are forced to land on Varos, a mining planet whose population is entertained and enslaved by a sadistic system of public torture and execution, and find themselves the latest unwilling subjects in this most extreme form of reality TV.

A strange signal from Earth draws the TARDIS to the island of Lanzarote, where Turlough rescues a young American girl, Peri, from drowning. Among her possessions is an artefact bearing an alien symbol - the same triangular mark that Turlough has branded into his arm. The mystery deepens when Kamelion falls under the control of a powerful mind, and the TARDIS travels to the volcanic world of Sarn. As Turlough is forced to face his past, the Fifth Doctor must stop his oldest enemy from harnessing the revitalising powers of Numismaton gas...

The Doctor discovers his old enemy the Master is intent on preventing Earth's industrial revolution in 19th century England. But the Rani, a second rogue Time Lord, has plans of her own...

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

Suddenly gripped by a memory of being executed in his second incarnation, the Sixth Doctor travels to Seville to save his past self and ensure his own existence in his present.

The Doctor and Peri arrive on Karfel, a planet ruled by fear where the enemies of its ruler, the despotic Borad, are banished into a time tunnel known as the Timelash.

Captured in a time corridor, the Doctor and his companions are forced to land on 20th century Earth, diverted by the Doctor's oldest enemy - the Daleks. It is here the true purpose of the time corridor becomes apparent: after ninety years of imprisonment, Davros, the ruthless creator of the Daleks, is to be liberated to assist in the resurrection of his army. Not even the Daleks foresee the poisonous threat of their creator. Indeed, who would suspect Davros of wanting to destroy his own Daleks - and why? Only the Doctor knows the truth. Will he descend to Davros' level of evil to stop him?

At the Tranquil Repose mortuary, the Doctor and Peri uncover a sinister plot to create a new breed of Daleks under the supervision of the mysterious Great Healer.

In 17th century England, the Doctor and itinerant thespian Richard Mace uncover a plot by a crew of criminal Terileptils to wipe out humanity.