Get ready for the biggest thriller of 2018! `Astounding. Thrilling. Amazing' Gillian Flynn `One of those rare books that really is unputdownable' Stephen King 'Twisted to the power of max' Val McDermid `A dark, twisty confection' Ruth Ware What did she see? It's been ten long months since Anna Fox last left her home. Ten months during which she has haunted the rooms of her old New York house like a ghost, lost in her memories, too terrified to step outside. Anna's lifeline to the real world is her window, where she sits day after day, watching her neighbours.