Bound by hate and a mystical amulet that holds the powers of life and death, two immortal wizards meet for the last time in an ancient struggle of good versus evil.

The TARDIS crew lands in the Himalayas of Cathay in 1289, their ship badly damaged, and are picked up by Marco Polo's caravan on its way along the fabled Silk Road to see the Emperor Kublai Khan. The story concerns the Doctor and his companions' attempts to thwart the machinations of Tegana, who attempts to sabotage the caravan along its travels through the Pamir Plateau and across the treacherous Gobi Desert, and ultimately to assassinate Kublai Khan in Peking, at the height of his imperial power.

The Doctor is summoned by the mysterious and powerful White Guardian, and sent on a quest to find the six segments of the Key to Time, which, once assembled, will restore balance to the Universe. Joining the Doctor and K9 is the smart and sassy Romana, a Time Lord fresh from the Academy. Landing on the wintry planet of Ribos to locate the first segment, the TARDIS crew quickly find themselves embroiled in a little local trouble with a pair of conmen and an unstable warlord...

Bill and Ted are high school buddies starting a band. They are also about to fail their history class—which means Ted would be sent to military school—but receive help from Rufus, a traveller from a future where their band is the foundation for a perfect society. With the use of Rufus' time machine, Bill and Ted travel to various points in history, returning with important figures to help them complete their final history presentation.

Amiable slackers Bill and Ted are once again roped into a fantastical adventure when De Nomolos, a villain from the future, sends evil robot duplicates of the two lads to terminate and replace them. The robot doubles actually succeed in killing Bill and Ted, but the two are determined to escape the afterlife, challenging the Grim Reaper to a series of games in order to return to the land of the living.

A young man struggles to access sublimated childhood memories. He finds a technique that allows him to travel back into the past, to occupy his childhood body and change history. However, he soon finds that every change he makes has unexpected consequences.

The TARDIS materialises not far from Paris in 1794 — one of the bloodiest years following the French Revolution of 1789. The travellers become involved with an escape chain rescuing prisoners from the guillotine and get caught up in the machinations of an English undercover spy, James Stirling — alias Lemaitre, governor of the Conciergerie prison.

When the Doctor, Sarah Jane and Harry arrive in Scotland, having received an urgent request for assistance from the Brigadier, they discover that the mysterious force which has destroyed three oil rigs has left giant teeth marks on the wreckage. The mystery deepens, leading them to the shores of Loch Ness where they find that the legendary monster really does exist – and is the murderous tool of the Zygons, aliens intent on overpowering the planet. The Doctor, his companions and UNIT must find a way to defeat the deadly Loch Ness Monster and its controllers, but the Zygons have the terrifying power to change shape. The Doctor's life has never been in more danger, as the line between allies and enemies is tested to the very limit...

When the TARDIS malfunctions, it and its travellers land on Earth at the size of insects. They uncover a murderous plot involving a new insecticide, but how can they stop the crime in their miniaturised condition?

The TARDIS arrives in a desolate future London, where the Doctor discovers his old enemies the Daleks have taken control of Earth.

Las Vegas showroom magician Cris Johnson has a secret which torments him: he can see a few minutes into the future. Sick of the examinations he underwent as a child and the interest of the government and medical establishment in his power, he lies low under an assumed name in Vegas, performing cheap tricks and living off small-time gambling "winnings." But when a terrorist group threatens to detonate a nuclear device in Los Angeles, government agent Callie Ferris must use all her wiles to capture Cris and convince him to help her stop the cataclysm.

The TARDIS arrives on the planet Marinus on an island of glass surrounded by a sea of acid. The travellers are forced by the elderly Arbitan to retrieve four of the five operating keys to a machine called the Conscience of Marinus, of which he is the keeper. These have been hidden in different locations around the planet to prevent them falling into the hands of the evil Yartek and his Voord warriors, who plan to seize the machine and use its originally benevolent mind-influencing power for their own sinister purposes.