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...

After Martha Jones parts company with the Doctor, his TARDIS collides with another, and he comes face to face with one of his previous incarnations.

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.

The Doctor, Romana, Adric and K9 encounter the enslaved time-sensitive Tharils, who lead them to a white void occupied only by the ruins of an old building and a spaceship - a dimension that might be the key to escaping E-Space.

Sam, a quiet West Indian working as a London Transport ticket collector, strikes up an unlikely, but warm, friendship with Joe, an old man who has a room in the same house.

In a Mars base, the inhabitants are being infected by a mysterious water creature which takes over its victims. The Doctor is thrust into the middle of this catastrophe, knowing a larger one is waiting around the corner.

The Doctor, Romana, Adric and K9 encounter the enslaved time-sensitive Tharils, who lead them to a white void occupied only by the ruins of an old building and a spaceship - a dimension that might be the key to escaping E-Space.

When scientists in the Antarctic uncover a mysterious seed pod, the Doctor is called in to investigate. He soon realises it is extraterrestrial and extremely dangerous. At the same time, however, ruthless millionaire plant-lover Harrison Chase has learned of the find and decides he must have the pod for his collection of rare and beautiful flora. Meanwhile the pod itself harbours intelligent life with sinister plans of its own...

A director talks about his old horror film. It's Austria, Krampusnacht, December 1977. The Devonshires arrive at the alpine chalet for a holiday. The caretaker, Klaus, tells them about a local legend of Krampus, the Devil of Christmas.