Doctor Who: Galaxy 4

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.

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.