The Doctor takes Donna back to Pompeii, on the day of the eruption of Mt. Vesuvius, and is faced with a great moral dilemma. Should they warn the residents of the impending disaster, or let history take its natural course?

The Doctor and Donna find themselves on an icy planet known as the Ood-Sphere. There they discover what drove the Ood to be a servant race.

Aided by the Rattigan Academy, the Sontarans establish a covert base at the mysterious ATMOS Factory. Can the Doctor stop the Sontarans from unleashing a potent terror that will bring the world to its knees?

The Sontarans continue their evil plot and begin to "choke" the Earth. The Doctor and Donna, now teamed with Martha have to stop them! Can they save Earth before it's too late?

The Doctor lands on the remote planet Messaline as an age-old war rages and the threat of genocide looms. When Martha is kidnapped by the Hath, the Doctor is distracted by "the most important woman in his life."

The Doctor and Donna's meet Agatha Christie at a manor owned buy Lady Eddison. When Agatha Christie goes missing and a body turns up in the library the adventure turns into a pulp sci-fiction murder mystery, with a murder, a jewel thief, and a wasp alien. Can they solve the mystery?

The Doctor and Donna land in a frightening position in the far future. While investigating a derelict library, the duo come face to face with the disembodied mind of a little girl, an archaeological team led by a woman from the Doctor's future, and swarms of flesh-eating creatures that are seen only as shadows.

As the shadows rise, the Doctor forges an alliance with the mysterious River Song.

While visiting Midnight, a beautiful and luxurious planet full of lavish and high-tech cities, a terrifying problem arises that leaves The Doctor powerless.

Whilst attending a carnival on the Chino-planet of Shan Shen, Donna is cajoled into having her fortune read, where her past is carefully examined. With the Doctor missing, Donna must work with Rose, a traveller from a parallel universe, to prevent darkness encompassing the whole of the universe.

The Earth has been moved, and it's a race against time as Donna and the Doctor try to find it before the Daleks destroy everything; they head for the Shadow Proclamation and the Medusa Cascade. Meanwhile on Earth a veritable bevy of ex-companions join together to contact the Doctor and take down the Daleks. Can Captain Jack, Sarah-Jane, Martha Jones and Rose find the Doctor in time...

The Earth has been overwhelmed and the universe faces dominion by the resurgent forces of a terrifying and limitless empire led by one of The Doctor's greatest enemies. Aiding the Time Lord in a final battle are several of his closest allies and companions, but for one of them, a price will be paid...