Ruth loves her life in London—she has a high-powered career and a handsome and successful fiancé. This Christmas, she’s bringing him back to her home town to meet her family and school friends, one of whom, Holly Murphy, has a new baby. But, as the Christmas Eve party is in full swing, the unthinkable happens—Ruth drops the baby, injuring the little boy. Or did she? Ruth becomes convinced she didn’t cause the baby’s injuries, that they were inflicted before the party, that the Murphys are not the lovely family they appear to be. Determined to discover what really happened to the child, Ruth digs for the truth. And won’t stop even when she’s shunned by her old friends, alienated from her fiancé, and sacked from her dream job. But are her suspicions justified? Or is she in the grip of a deadly obsession that threatens to utterly destroy her perfect life?