"A page-turner for readers who like beach reads on the dark side" ( People ), this unputdownable domestic thriller from the #1 New York Times bestselling author of Then She Was Gone asks the question: just how much do you trust your neighbors? Imagine that you live on a picturesque communal garden square, an oasis in urban London where your children run free, in and out of other people's houses. You've known your neighbors for years and you trust them. Implicitly. You think your children are safe. But are they really? On a midsummer night, as a festive neighborhood party is taking place, preteen Pip discovers her thirteen-year-old sister Grace lying unconscious and bloody in a hidden corner of a lush rose garden. What really happened to her? And who is responsible? Dark secrets, a devastating mystery, and the games both children and adults play twist together in this unforgettable novel, packed with utterly believable characters and page-turning suspense.