The TARDIS takes the Doctor and Rose to a destination in deep space - Justicia, a prison camp stretched over seven planets, where Earth colonies deal with their criminals. While Rose finds herself locked up in a teenage borstal, the Doctor is trapped in a scientific labor camp.

When the Tardis touches down in London, schoolteachers Ian and Barbara are eager to explore their own future. But they have arrived in the middle of a war. Mistaken for vagrants, the Doctor's granddaughter and companions are in the execution block on the Isle of Dogs. The Doctor has no choice but to help the military refine its ultimate weapon.

On another world, an alien war is raging. The Quevvils need to find a new means of attacking the ruthless Mantodeans. Searching the galaxy for cunning, warlike but gullible allies, they find the ideal soldiers - on Earth. Will Rose be able to save her family and friends from the alien threat? And can the Doctor play the game to the end - and win?

The Doctor walked slowly forward into the cul-de-sac. The giant dinosaur turned its head to focus on the midget now approaching. The Doctor aimed his gun to fire. Suddenly from behind came a great roar of anger. He spun round - blocking the exit from the narrow street towered a Tyrannosaurus rex, its savage jaws dripping with blood.

The Time Lords direct Doctor Who and Jo Grant in their TARDIS to a bleak planet in the year 2471, where they find colonists from Earth under threat from mysterious, savage, monster lizards with frightful claws! And hidden upon the planet is the Doomsday Weapon, for which the Master is intently searching.

The Brigadier stared in amazement as the Robot began to grow, swelling to the size of a giant! Slowly the metal colossus, casting its shadow upon the surrounding trees and buildings, began to stride towards the Brigadier. Can Doctor Who defeat the evil forces controlling the Robot before they execute their plans to blackmail or destroy the world?