The New York Times bestselling author returns with an unsettling but riveting psychological thriller about a captivating woman who joins a family and threatens to upend their picture-perfect lives. Summer's looking forward to a break from hustling for acting work in Manhattan when she, her husband Gabe, and Gabe's nine-year-old son come to rural Pennsylvania for the annual family get-together at her in-laws' sprawling estate. On the agenda are leisurely gourmet meals, tennis games, and plenty of relaxation by the pool. This year, Gabe's baby brother Nick, a perpetual bachelor, has invited his new flame Hannah, who's an actress as well. In fact, Summer immediately recognizes Hannah from a showcase they once did together, but strangely, Hannah claims not to know her. And that's not the only thing that seems off. Yet she charms the other family members, and after Nick announces that he's proposed to Hannah, Summer doesn't have much choice but to grit her teeth and smile. Then the reunion is rocked by tragedy when another family member is found dead, and the doctors attribute the loss to natural causes. A grieving Summer believes that they may have overlooked something, and fears that the too-good-to-be-true Hannah is involved, but Gabe and the others keep ignoring her suspicions. How far will Summer go to expose the truth? As she investigates just what Nick's fiancée might have done to keep her perfect image intact, she begins to fear that the first death may only be the beginning ...