Season 21

(4 episodes)

Earth, 2084. Two global superpowers hover on the brink of war. When the TARDIS is forced to make an unplanned visit to Sea Base Four, the Doctor, Tegan and Turlough find themselves accused of being enemy agents. Quickly embroiled in a deadly game of paranoid intrigue, it becomes clear that others on the base have sabotage and murder in mind. However, there is a greater threat to humankind: the Silurians and Sea Devils, prehistoric reptiles seeking to reclaim the Earth. Can the Doctor prevent them from implementing their 'final solution' and triggering a war that could wipe out the entire human race?

Written by Johnny Byrne

(2 episodes)

Little Hodcombe, 1984. The Doctor, Tegan and Turlough arrive in a small English village, looking forward to spending some time with Tegan's grandfather. They soon discover that all is not well. Tegan's grandfather is missing and the locals are reenacting dangerous war games from 1643. With the past mixed up with the present, can the Doctor stop the games before an evil entity hidden in the village church awakens?

Written by Eric Pringle

(4 episodes)

An irresistible force draws the TARDIS to the barren surface of Frontios, where in the far future the last surviving humans cower amongst the ruins of their wrecked spacecraft. Under constant threat from lethal meteorite bombardments, few of the doomed colony members realize that the ground of Frontios itself opens up and devours the unwary. Not permitted to assist, the Doctor attempts to leave, but is thwarted when the unimaginable occurs: the TARDIS is utterly destroyed. All the while, burrowing undetected below the planet's crust, sickening alien parasites prepare a gruesome and final fate for all humanity.

Written by Christopher H. Bidmead

(2 episodes)

Earth, 1984: The TARDIS becomes trapped in a Time Corridor and is drawn off course, emerging in London's deserted docklands. Meanwhile, in deep space of the far future, a prison ship comes under attack from unknown forces. Two seemingly unconnected events, both linked by one terrible purpose. The Daleks are back, and once again they are in search of their evil creator, Davros...

Written by Eric Saward

(4 episodes)

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 artifact 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 Doctor must stop his oldest enemy from harnessing the revitalizing powers of Numismaton gas.

Written by Peter Grimwade

(4 episodes)

Arriving on the barren world of Androzani Minor, the Doctor and Peri find themselves embroiled in a long-running underground war. Military troops mount an armed blockade whilst gunrunners bring in weapons for the sinister, masked renegade, Sharaz Jek. Meanwhile, lethal androids guard the caves, and a deadly creature lurks in the shadows, killing all in its path. At the heart of the conflict is a substance called Spectrox, the deadliest and most valuable item in the universe! The very presence of the Doctor and Peri on Androzani sets in motion a chain of events that will have dramatic consequences for everyone involved. As the situation gets even more desperate, the Doctor realises time is running out for both Peri and himself. Will the Doctor make the ultimate sacrifice to save his young friend's life...?

Written by Robert Holmes

(4 episodes)

The Doctor has regenerated and all is not well. Confused, angry and acting strangely, the new Doctor decides to become a hermit, so takes his concerned companion Peri to a desolate asteroid where he plans to live for several centuries. However, the time travellers soon uncover a plot that threatens the entire galaxy! Why has an alien Gastropod kidnapped a pair of genius twins, and will the Doctor recover in time to find out?

Written by Anthony Steven