After narrowly escaping a bizarre accident, a troubled teenager is plagued by visions of a large bunny rabbit that manipulates him to commit a series of crimes.
The TARDIS lands on the idyllic jungle world of Deva Loka, which is being surveyed for possible Earth colonisation. Deva Loka is already home to a race of apparent savages, however: a mysterious people with strange powers which have mentally unbalanced the members of the expedition. To make matters worse, an ancient enemy of the natives known as the Mara is intent upon revenge, and latches onto Tegan's mind as its bridgehead to victory.
While investigating a vanishing Concorde at Heathrow Airport, the Doctor and his companions are thrown millions of years back in time, when a mysterious alien called Kalid is trying to control the ancient powers of the Xeraphin.
Omega, an ancient Time Lord made of pure anti-matter, once defeated by the Doctor, is plotting to cross over into this dimension by bonding with the Doctor. Meanwhile, the disappearance of a man in Amsterdam piques the curiosity of his cousin, Tegan, who previously left the Doctor at Heathrow Airport and now finds herself at Omega's mercy. Fearing total destruction from the collision of matter and antimatter, the Time Lords recall the Doctor to Gallifrey to undertake the only viable solution: executing him!
When a son attempts to reconcile with his father, a series of fateful events allow him to experience the father's life in the past.
A warp ellipse draws the TARDIS off course. The Fifth Doctor's companions are separated from him not in space, but in time, and he has to deal with a treacherous schoolboy named Turlough. But why does the Doctor's old friend, the Brigadier, not remember him at all?
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.
The Fifth Doctor, Tegan and Turlough arrive on Sea Base 4, a nuclear warhead station under the sea that has some very nasty neighbours.
Finding the fourth segment of the Key to Time was simple enough, but holding onto it may be another matter. The Doctor and Romana find themselves embroiled in the political games of the planet Tara, where doubles, android or otherwise, complicate the coronation of Prince Reynart.
The Doctor, Tegan and Turlough arrive in Little Hodcombe, where the townspeople's re-enactments of English Civil War battles are causing a dormant entity, the Malus, to re-awaken.
"Frontios buries its own dead", or so the saying goes. The Doctor, Turlough and Tegan are forced into landing on the remote planet of Frontios, a human colony where deaths go unaccounted for. What lies beneath the surface, dragging its victims down?
The Doctor and Romana arrive on the marsh moon of Delta Magna in search of the next segment of the Key to Time. They are caught in the conflict between the native Swampies and the crew of a chemical refinery. The presence of a gun runner complicates matters; to make things worse, the Swampies intend to awaken Kroll, the giant god that lives beneath the swamps.
The final segment of the Key to Time is at the heart of a devastating war between neighbouring planets Atrios and Zeos. The Fourth Doctor discovers that a sinister entity is manipulating events and the cost of obtaining the final segment may be more personal than he imagined.
The Doctor and a newly-regenerated Romana arrive on Skaro to find that the Daleks, locked in a war with the robotic Movellans, have returned to retrieve their buried creator Davros.
The Doctor and Romana follow a distress signal which leads to the jungle planet Chloris, whose ruthless ruler Lady Adrasta harbors a deadly creature in a pit.
A freak accident leaves two dangerously unstable spacecraft locked together, and a horde of monsters unleashed on their passengers.
Romana fancies a proper holiday and convinces the Doctor to visit the leisure planet Argolis, where a takeover by the Argolins' historic enemy is underway.
On the lush planet Tigella, two opposing factions are divided over the usage of the Dodecahedron, an ancient and powerful artefact which provides the entire planet's energy. The Doctor is summoned to arbitrate the conflict, but the power-crazed Meglos intercepts the call and impersonates him in order to steal the Dodecahedron.
A man confronts his past during an experiment that attempts to find a solution to the problems of a post-apocalyptic world caused by a world war.
Year three at Hogwarts means new fun and challenges as Harry learns the delicate art of approaching a Hippogriff, transforming shape-shifting Boggarts into hilarity and even turning back time. But the term also brings danger: soul-sucking Dementors hover over the school, an ally of the accursed He-Who-Cannot-Be-Named lurks within the castle walls, and fearsome wizard Sirius Black escapes Azkaban. And Harry will confront them all.