Two thousand years ago, a volcanic eruption wiped the Roman city of Pompeii from the face of the Earth. It also buried the Doctor's Tardis.... Arriving in Pompeii one day before the disaster, the Doctor and Mel find themselves separated from their ship and entangled in local politics. As time runs out, they fight to escape from the shadow of Mount Vesuvius. But how can they succeed when history itself is working against them?

Landing in Alaska, the Doctor and Nyssa encounter a group of people in a most unusual house, cut off not only by the harsh climate but by their individual secrets and obsessions. Millionaire Shaun Brett is utilising chunks of the local area to construct a shrine to his dead father. But when deadly creatures start roaming outside and a terrifying discovery is made inside the house, the Doctor realises that Brett has unleashed an unimaginably ancient force. Written by Stephen Cole. Directed by Gary Russell.

The universe stands on the brink of a dimensional crisis - and the Doctor and Raine are pulled into the very epicentre of it. Meanwhile, on Earth, UNIT scientific advisor Dr Elizabeth Klein and an incarnation of the Doctor she's never encountered before are tested to the limit by a series of bizarre, alien invasions. At the heart of it all is a terrible secret, almost as old as the Time Lords themselves.

On 19th century Earth artist Edvard Munch hears an infinite scream pass through nature. Centuries later his painting of that scream hangs in a gallery on the barren dust world Duchamp 331. Why is there a colony of artists on a planet that is little more than a glorified garage? What is the event that the passengers of the huge, opulent pleasure cruiser 'Gallery' are hoping to see? And what is hidden in the crates that litter the cargo hold?

In a desolate Cornish landscape littered with relics of prehistoric man, the Doctor and Evelyn uncover a catalogue of mysteries. What is the secret of the fog? Can the moor be haunted by a demonic host of imps? And what is Brigadier Lethbridge-Stewart doing in Pengriffen? Teaming up with his old friend, the Doctor realises that an ancient conflict is nearing its conclusion - and Lanyon Moor is set to be the final battleground. Written and directed by Nicholas Pegg.