This is a novel about two very different girls, and how sometimes, the sum can be more terrifying than each of its parts. 'You may think you know what they do in the dark . . . But who are "they"? . . . Set in the mid-1970s, What They Do in the Dark combines cosy nostalgia (jumbo lollies, gas fires) with rumbles of apprehension. Something awful's going to happen, but it's not clear what . . . A terrific debut, full of energy and colour; as propulsive as a thriller' Carrie O'Grady, Guardian