Sarah Jane, Maria, Luke, and Clyde investigate strange lights sighted near the village of Goblin's Copse, where a radio telescope observatory is located. When they discover Professor Nicholas Skinner, who runs the observatory, has gone missing in the woods, Luke and Clyde search for him. They discover Sontaran Commander Kaagh, the sole survivor of an invasion force involving the infiltration of Earth's cars that was otherwise destroyed, and his space pod. Sarah Jane and Maria gather at the pod, where Kaagh confesses he contrived the lights to draw the Professor out of the observatory.
