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...

Tom Baker in conversation with a fascinated audience — humour, drama, passion, and honesty on a range of topics from K9 to death, and from leaving Doctor Who after his mammoth seven-year reign to his love of cats.

The Doctor needs somewhere peaceful to recover from his traumatic regeneration. But the sanctuary of Castrovalva is not all it seems, as the Master will stop at nothing to gain his revenge over the Doctor...

Tegan falls once more under the influence of the Mara and directs the TARDIS to the planet Manussa. There, the Federator's son Lon and his mother Tanha are preparing for a ceremony to celebrate the banishment of the Mara five hundred years earlier. The Mara takes control of Lon and uses him and Tegan to obtain from Ambril, the Director of Historical Research, the 'Great Crystal' - the large blue stone that originally brought it into being by focusing energy from the minds of the planet's one-time inhabitants. The Mara now plans to use the crystal during the ceremony to bring about its return to corporeal existence.

An Edwardian yacht in deep space races around the planets. There is a double agent in the TARDIS crew. The White Guardian warns the Fifth Doctor of great danger. Turlough must finally choose sides and at the end of the race lies the prize of Enlightenment.

When a farmer's land is wanted for a new town development, a lot of people find their lives put in the melting pot.

The Time Lords send the Doctor and Jo on a mission to deliver a sealed message pod to an unknown party aboard a Skybase orbiting the planet Solos in the 30th century. They are caught quickly in a power struggle between the cruel Marshal of Solos and the young Solonian Ky over the future of Solos - a future that hinges on the contents of the message.

The TARDIS materialises in Paris in the year 1572 and the Doctor decides to visit the famous apothecary Charles Preslin. Steven, meanwhile, is befriended by a group of Huguenots from the household of the Protestant Admiral de Coligny. Having rescued a young serving girl, Anne Chaplet, from some pursuing guards, the Huguenots gain their first inkling of a heinous plan being hatched at the command of the Catholic Queen Mother, Catherine de Medici.

The Intergalactic War is over. The Combined forces of Earth's galaxy have triumphed over the invasion force from Andromeda, but the price of victory has been high.