Summer, her husband Gabe, and Gabe's nine-year-old son arrive at the annual family get-together at her in-laws' sprawling estate. On the agenda are leisurely gourmet meals, tennis matches, and plenty of relaxation by the pool. Gabe's brother Nick has invited his new flame Hannah, whom Summer immediately recognizes from a few years before. Hannah claims not to know Summer, and charms the other family members. When a family member is found dead of apparent natural causes, Summer fears that the too-good-to-be-true Hannah is involved. As she investigates, Summer begins to fear that the first death might only be the beginning. --adapted from jacket.