Industrialist François Delambre is called late at night by his sister-in-law, Helene Delambre, who tells him that she has just killed her husband, André. Reluctant at first, she eventually explains to the police that André invented a matter transportation apparatus and, while experimenting on himself, a fly entered the chamber during the matter transference.
A research scientist explores the boundaries and frontiers of consciousness. Using sensory deprivation and hallucinogenic mixtures from native American shamans, he explores these altered states of consciousness and finds that memory, time, and perhaps reality itself are states of mind.
Sontaran Field Major Styre is conducting experiments on the survivors of future Earth in preparation of a full-scale Sontaran invasion of the planet. Can the Doctor defeat Styre and save the world?
The Time Lords dispatch the Doctor to the past of the planet Skaro on his deadliest adventure yet — to prevent the creation of the Daleks.
A remote arctic station is overrun by its own monstrous experiment, leaving the survivors no choice but to face what they've created.
The TARDIS attaches itself to a space liner after Turlough, still under the Black Guardian's influence, damages its controls. The Doctor and Nyssa meet two space pirates, Kari and Olvir, who have come on board the liner in search of plunder, while Tegan and Turlough get lost in the infrastructure. The liner docks with what appears to be a hulk floating in space. This is Terminus, which claims to offer a cure for Lazar's disease. It is crewed by armoured slave workers, the Vanir. The cure is administered by a huge, dog-like creature known as the Garm. Nyssa, who has contracted the disease from sufferers transported aboard the liner, discovers that the cure - involving exposure to radiation - does actually work.
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 Doctor and his companions arrive at a medieval joust and are surprised to be greeted warmly by King John, who calls them his demons. But when a young nobleman returns, having just left King John in London, the Doctor realises that this king must be an impostor! Then the Master makes an appearance and the Doctor's worst fears are confirmed...
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?
When the discovery of a five-thousand year old artifact of a humanoid reptile leads an investigative reporter to the Kronos Project, he uncovers an experimental device created to send humans through time, controlled by a ruthless multi-billionaire. As the Kronos experiment progresses through the Civil War era to the Jurassic age, high-tech sabotage and deceit ensue, resulting in devastating events that lead to a ripple in time, a paradox, that if not contained could change the entire course of evolution and destroy the universe as we know it.
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.