Season 12

(4 episodes)

Full of energy but a touch erratic after his regeneration, the Doctor's recuperation is cut short as UNIT investigate a spate of robberies involving components for a top-secret disintegrator gun. The culprit is quickly identified as a highly sophisticated robot built by Professor Kettlewell, but was is the sinister agenda of the Scientific Reform Society? And can the Doctor rescue Sarah from the robot's clutches and avert catastrophe?

Written by Terrance Dicks

(4 episodes)

Many thousands of years in the future, Earth becomes uninhabitable. Aboard space station Nerva, the remaining survivors of the human race drift among the stars in suspended animation. The Doctor, Sarah and Harry arrive to find vital systems have been sabotaged. As mankind begins to awake from its enforced deep sleep, the Doctor discovers that they are not alone... The Wirrn are an insect race that inhabit the cold depths of space. But they too have found the Ark and its sleeping occupants. Can the Doctor prevent the last of the human race from becoming the Wirrn's new source of food...?

Written by Robert Holmes

(2 episodes)

Transmitting down from Nerva Beacon, the Doctor, Sarah and Harry find themselves on Earth in the far future, long-since abandoned by the human race. But it soon becomes clear that they are not alone: a shipwrecked crew of Galsec colonists are being hunted down, one by one. What is the creature that lives in the rocks, and what is the purpose of the lethal tests it is conducting? Can the Doctor ensure the safety of the Earth for the future generations of Mankind?

Written by Bob Baker and Dave Martin

(6 episodes)

The Doctor's own people, the Time Lords, have foreseen a time in which the Daleks dominate all other lifeforms in the universe. So disturbing is this possibility, that they break their own Laws of Time in an attempt to change the future. And who better to send on this quest than their own renegade number, the Doctor. Unwillingly transported into the fields and trenches of a battle-exhausted Skaro, the Doctor must face his most dangerous mission ever, to prevent the Daleks from ever being created.

Written by Terry Nation

(4 episodes)

The Doctor, Sarah and Harry hope to find the TARDIS waiting for them on Nerva Beacon, but instead find they are thousands of years earlier in time, on a space station in the grip of a deadly plague that has wiped out most of its crew. But the Doctor soon comes to suspect that the 'plague' is no natural illness and that some of his oldest and most fearsome foes are behind it. And can the few humans on board be trusted?

Written by Gerry Davis