The chilling psychological thriller from the #1 bestselling author of I Am Watching You. On a train with her husband, miles from home and their four-year-old son, Ben, Sophie receives a chilling phone call. Two boys are in hospital after a tragic accident. One of them is Ben. She thought she could trust Emma, her new friend, to look after her little boy. After all, Emma's a kindred spirit-someone Sophie was sure she could bare her soul to, despite the village rumours. But Sophie can't shake the feeling that she's made an unforgivable mistake and now her whole family is in danger. Because how well does she know Emma, really? Should she have trusted her at all? Time is running out. Powerless to help her child, still hours from home, Sophie is about to discover the truth. And her life will never be the same.