(4 episodes)
The Doctor has defeated the Master's plans to hold the Universe to ransom, but at a high personal cost. After plummeting from the Pharos Project telescope, the Doctor regenerates. The time travellers escape the Master's clutches, but the Doctor's regeneration is failing, and Adric goes missing in the depths of the TARDIS. Only Nyssa and Tegan can save the day by steering the TARDIS to the city of Castrovalva, renowned for its healing powers. But evil lurks in the heart of this simple paradise...
Written by Christopher H. Bidmead
(4 episodes)
The Doctor has returned Tegan to 1981, the right time, but the wrong place. The TARDIS has landed on a massive spaceship four days away from Earth. It is the domain of Monarch, a scientific genius of almost god-like power. Monarch rules over three billion of his species, as well as a group of apparently immortal humans from Earth's history. What part has Monarch played in Earth's past, and what are his plans for the future? Will he save humanity from itself, or be its destroyer? It's four to doomsday, and the Doctor has no time to lose finding out.
Written by Terence Dudley
(4 episodes)
The TARDIS visits the planet Deva Loka. Nyssa remains behind in the ship to recover from a mild mental disorientation while the Doctor, Tegan and Adric explore. Tegan falls asleep under some mysterious chimes and becomes possessed by an evil force, The Mara.
Written by Christopher Bailey
(4 episodes)
England, 1666 - the darkest days of the Great Plague. When the Doctor and his companions step from the TARDIS into a land gripped by fear and mistrust, they soon discover that they are not the only new arrivals. Strange lights have been seen in the sky, the Grim Reaper stalks the local woods and evidence of advanced technology is all around...
Written by Eric Saward
(2 episodes)
England, 1925. The TARDIS materialises on a quiet railway platform where the Doctor, Tegan, Adric and Nyssa soon discover they are expected at an afternoon cricket match. And when the time travellers are invited to stay at Cranleigh Hall for a fancy dress ball, it isn't long before they uncover a terrible family secret. Who is murdering the servants, and why? A rare flower may hold the answer...
Written by Terence Dudley
(4 episodes)
The mysterious disappearance of an archaeological team is merely the prelude to a deadlier threat for the Doctor and his companions, the Cybermen want to destroy Earth, and will use any means at their disposal. The Doctor's ingenuity is stretched to its very limits as he battles to defeat the Cyber army at any cost. But even he does not realise just how high that cost will be...
Written by Eric Saward
(4 episodes)
The TARDIS arrives by accident in the middle of Terminal One at Heathrow Airport. One of the supersonic Concordes has disappeared midair, and the Doctor, Tegan and Nyssa soon become involved in a hunt for the missing aeroplane. But what connects its disappearance to prehistoric Earth, and why is a mysterious sorcerer so interested in the Doctor's TARDIS? A flight through time will reveal all...
Written by Peter Grimwade