Transmitting down from Nerva Beacon, the Doctor, Sarah and Harry find themselves on Earth in the far future, long-since abandoned by the human race. But it soon becomes clear that they are not alone: a shipwrecked crew of Galsec colonists are being hunted own, one by one. What is the creature that lives in the rocks, and what is the purpose of the lethal tests it is conducting? Can the Doctor ensure the safety of the Earth for the future generations of Mankind?, Transmitting down from Nerva Beacon, the Doctor, Sarah and Harry find themselves on Earth in the far future, long-since abandoned by the human race. But it soon becomes clear that they are not alone: a shipwrecked crew of Galsec colonists are being hunted own, one by one. What is the creature that lives in the rocks, and what is the purpose of the lethal tests it is conducting? Can the Doctor ensure the safety of the Earth for the future generations of Mankind?

Special Features:

• 'Built For War' - The genesis and development of the Sontoran race through the h
• Commentary by Elisabeth Sladen (Sarah Jane Smith), Philip Hinchcliffe (producer)
• Photo Gallery.