War is a popular backdrop for novels, particularly love stories. The heightened emotions fuelled by apocalyptic conditions provide rich targets for a novelist’s searchlight. Waters has turned hers full beam onto London during and just after the Second World War, and in particular onto issues of cowardice and bravery. Par for the course, you might think, in war. But with Waters we have learned (from her earlier novels Fingersmith and Tipping The Velvet) to expect the unexpected.