 The series begins as an unexplained meteor crashes into the side of a New Zealand volcano, unleashing the snake-like Shalka, an alien species with a deadly scream. Thousands of miles away in a Lancashire town, the TARDIS materialises on a Saturday night. The streets are empty, the pubs are deserted and random, unexplained pools of lava keep appearing on the ground. Time isn t on the Doctor s side and neither, it seems, are the town s inhabitants; with the possible exception of feisty barmaid Alison. When the TARDIS disappears in a pool of lava and the Doctor and Alison are confronted by the hunting Shalka, it seems that there s just no way out.