Happily married with a beautiful young daughter, a handsome husband, and a sprawling house in one of Boston's most comfortable suburbs, Bonnie Wheeler has an enviable life. Even her husband's ex-wife, Joan, with her tendency toward bad timing, is merely a nuisance. But one morning Bonnie must grasp the fragility of her perfect world. When she finds Joan shot through the heart, it becomes terrifyingly clear that someone is also after her - and her exquisite child.