A group of paleontologists have been savagely attacked while carrying out a study of fossilised dinosaur remains in an underground cave system on twenty-fifth-century Earth.

A party of troopers and Professor Kyle, the only survivor of the attack, are investigating the deaths of her colleagues when they discover the Doctor and his companions at the site of the massacre. The time-travellers are immediately suspected.

In trying to establish their innocence and find out who - or what - was responsible for the killings, the Doctor is confronted by an old enemy...

The Doctor remembers Dulkis from a previous visit as a civilised peaceful place. But times have changed, and his second trip is not quite the holiday he was expecting.

The Dulcians themselves are more reluctant than ever before to engage in acts of violence. The so-called Island of Death, once used as an atomic test site, has served as a dire warning to generations of Dulcians of the horrifying consequences of warfare. But an alien race prepares to take advantage of their pacifism...

The whole planet and its passive inhabitants are threatened with complete annihilation - and no one, it seems, is going to lift a finger to stop the evil Dominators and their unquestioning robot slaves.

Materialising in outer space, the TARDIS is attacked by a missile fired from the dark side of the moon. Back on Earth, the newly-formed United Nations Intelligence Taskforce, led by Brigadier Lethbridge-Stewart, is disturbed by a series of UFO sightings over Southern England. Meanwhile, a large consignment of mysterious crates is delivered to the headquarters of International Electromatix, the largest computer and electronics firm in the world. Three seemingly unconnected events - but in reality the preparations for a massive Cyberman invasion of Earth with one aim - the total annihilation of the human race.

It is 1794 and the TARDIS materialises some distance away from Paris during the French Revolution - the infamous Reign of Terror. Soon the TARDIS crew find themselves caught up in the tangled web of historical events. Imprisoned in a dank dungeon, Ian is entrusted with delivering a message to master-spy James Stirling. Who is James Stirling? What world-shattering events are being discussed in a deserted inn off the Calais road? And can the Doctor and his friends escape a violent and bloody death at the dreaded guillotine?

From his one previous visit the Doctor remembers the inhabitants of the planet Dido as a gentle, peace-loving people. But when he returns, things have changed dramatically. It seems that the Didoi have brutally massacred the crew of the crashed spaceliner Astra. Even now they are threatening the lives of the sole survivors, Bennett and the orphan girl Vicki. Why have the Didoi apparently turned against their peaceful natures? Can Bennett and Vicki survive until the rescue ship from Earth arrives? And who is the mysterious Koquillion?

At a time in the far-off future, Earth has become uninhabitable. A selection of Humanity is placed, deep-frozen, in a fully automated space station, to await the day of their return to Earth...

Thousands of years later, DOCTOR WHO arrives. He finds things going suspiciously wrong, and the station under attack from the giant WIRRN, deadly creatures who, in their lust for power, now threaten the future of the whole Human Race...

In the year 2030 only one man seems to know what action to take when the world is hit by a series of terrible natural disasters. Salamander's success in handling these monumental problems has brought him enormous power.

From the moment the Doctor, Jamie and Victoria land on an Australian beach, they are caught up in a struggle for world domination - a struggle in which the Doctor's startling resemblance to Salamander plays a vital role.

Reluctantly cancelling his well-earned holiday, the Doctor sets off in the TARDIS to trace and re-assemble the six segments of the Key to Time on which the stability of the entire Universe depends.

Assisted by the argumentative Romanadvoratrelundar and K9, he lands on the planet Ribos in search of the first segment and finds himself entangled in the machinations of two sinister strangers, Garron and the Graff Vynda Ka.

Who are they? Is Garron simply a shady confidence-trickster dealing in interplanetary real estate? Is the Graff Vynda Ka just a power-crazed exile bent on revenge? Or are they both really agents of the Black Guardian, intent upon seizing the precious Key in order to throw the Universe into eternal chaos?

Risking his life within the monster-infested catacombs of Ribos, the Doctor has to use all his wit and ingenuity to find out...

Landing on Earth, now a barren, desolate planet, Sarah, Harry and the Doctor are unaware of the large, watching robot. The robot is the work of Styre, a Sontaran warrior, who uses all humans landing here for his experimental programmes.

What happened to the other space explorers who have come here? Why is the Sontaran scout so interested in Earth and in brutally torturing humans, including Sarah Jane? Will the Doctor be able to prevent an invasion and certain disaster, and save both Earth and his companions?

It is ten years since Harry Sullivan left UNIT and gave up his travels in the TARDIS with the Doctor and Sarah Jane.

Since then he has been engaged in top secret work, developing antidotes to nerve toxins.  But when he is transfrerred to Yarra in the Hebrides to work on weapons research, he has severe misgivings.  For one thing, it goes against much of what he believes in.  For another, someone is out to kill Harry Sullivan.

Who wants Harry safely out of the way?  What significance does a painting by Van Gogh have in the affair?  And can Harry's old friend, the Brigadier, really be involved in a scheme which threatens the security of the Western World?