The book is written in the first person, with Claire as the narrator. She questions the idea of suicide and enlists the aid of Sallie, Lydia's mother, and then Jill, Lydia's neurologist husband Matthew's partner in a biotechnology company, to confirm her suspicions. She uncovers one incident after another until the murder suspects include Matthew, Randy, a psychiatrist who lives across the street and who may have had an affair with Lydia, and Lydia and Matthew's son's soccer coach. The plot is complicated but well researched. It includes an accurate description of the behavior of a woman with severe depression, the effect of tyramine combined with antidepressants, the attempt to make the death look like a cerebral vascular accident, and insider trading.