Shada: a prison built by the Time Lords for defeated would-be conquerors of the universe. A scientist named Skagra needs the help of one of the prison's inmates. He finds nobody knows where Shada is anymore, except one aged Time Lord who has retired to Earth, where he is a professor at St Cedd's College. Luckily for the universe, Skagra's attempt to force the information out of Professor Chronotis coincides with a visit by the professor's old friend, The Doctor.

Knights from a parallel universe arrive on Earth to find the legendary sword Excalibur. Only the Doctor and Ace, with the assistance of Brigadier Lethbridge-Stewart, can save the Earth from total catastrophe.

The Rani has returned with another malicious scientific scheme. Taking advantage of the post-regenerative trauma the recently regenerated and unstable Doctor is going through, she hopes to achieve control of an approaching asteroid composed entirely of strange matter. Can the Doctor figure out he is being used for the Rani's evil experiment, and what is behind the door the Rani won't allow him past?

The Doctor and Mel go for a holiday trip to Shangri-La aboard a Nostalgia Tours bus, only to get dragged into the battle against genocide of their fellow passenger Delta, a Chimeron Queen fleeing from the Bannermen who wish to make her species extinct.

The arrival of a mysterious comet heralds impending danger from enemies both old and new. As Ace helps the Doctor defend Earth, she is confronted with a dangerous question..."Doctor Who?"

The TARDIS arrives on the planet Terra Alpha, where the Seventh Doctor and Ace discover a society in which sadness is against the law - a law enforced zealously by the brightly uniformed Happiness Patrol. The planet is ruled by Helen A with the aid of her companion, Joseph C, and her carnivorous pet Stigorax, Fifi.

London, 1963: The Doctor returns to the place where it all began — alongside his latest companion, Ace, with unfinished business. Not for the first time, unusual events are unfolding at Coal Hill School. At 76 Totter's Lane, the Doctor discovers that his oldest foes — the Daleks — are on the trail of stolen Time Lord technology that he left on Earth long ago. The Daleks are planning to perfect their own time-travel capability, in order to unleash themselves across the whole of time and space.

London, 1963: The Doctor returns to the place where it all began — alongside his latest companion, Ace, with unfinished business. Not for the first time, unusual events are unfolding at Coal Hill School. At 76 Totter's Lane, the Doctor discovers that his oldest foes — the Daleks — are on the trail of stolen Time Lord technology that he left on Earth long ago. The Daleks are planning to perfect their own time-travel capability, in order to unleash themselves across the whole of time and space.

The Doctor and Mel visit Paradise Towers, a residential complex that promises a peaceful life to its residents. However, the establishment is far from what its name suggests: A conflict persists among the Kangs, humanesque multicolour beings who gather in opposing gangs based on which colour of the rainbow they bear; killer cleaning robots prowl the halls, and a secret in the complex's basement poses the greatest threat of all.

The Doctor and Mel visit Paradise Towers, a residential complex that promises a peaceful life to its residents. However, the establishment is far from what its name suggests: A conflict persists among the Kangs, humanesque multicolour beings who gather in opposing gangs based on which colour of the rainbow they bear; killer cleaning robots prowl the halls, and a secret in the complex's basement poses the greatest threat of all.