A woman's investigation into her past reveals family secrets and lies in this novel of discovery, redemption, and the mutability of memory by the bestselling author of The Good Neighbor and In Another Light. Astrid Johansen swore she would never return to Heron Bay, Washington. In that idyllic coastal town, her little sister, Nina, drowned in a reflecting pool under Astrid's watch seventeen years ago. Though guilt has kept her away, Astrid can't ignore her aunt Maude's urgent plea to come back. Maude claims to have found a letter that will change everything about the past. When Astrid arrives in Heron Bay, she finds Maude unconscious, perhaps the victim of an attack. As Maude lingers in a coma, Astrid uncovers alarming evidence that Nina's drowning that tragic night was no accident. But in a town rife with secrets, and in a family still fractured by grief, who knows the truth? Astrid's investigation leads her down a trail of dark memories, lies, and betrayals that will shatter her perception of everyone she thought she knew-even herself.