A locked room mystery, set in a Paris apartment building in which every resident has something to hide... Welcome to No.12 Rue des Amants, a beautiful old apartment block, deep in the backstreets of Montmartre. A place of twisting staircases, locked rooms, watchful eyes from every window. A place of murder. One resident is missing. And another holds the key... From the New York Times bestselling author of 'The Guest List'.