The evil Master leered at the Doctor, and triumphantly pointed out of the cabin window. The many-tentacled Nestene monster—spearhead of the second Auton invasion of Earth—crouched beside the radio tower! Part crab, part spider, part octopus, its single huge eye blazed with alien intelligence and deadly hatred... Can the Doctor outwit his rival Time Lord, the Master, and save the Earth from the Nestene horror?