The central character of Mary Higgins Clark's first thriller is the heroine Nancy Eldredge, who lives on Cape Cod with her husband, Raynor (Ray), and their children, Mike and Missy. Nancy was born to David and Priscilla Kiernan. Her father was an airline pilot who died of pneumonia when she was a little girl, and her mother, a receptionist in a psychiatrist's office, was killed in an automobile accident while on her way for a visit with Nancy. While a student at a college in San Francisco, Nancy meets and later marries one of her professors, Carl Harmon. The marriage, however, turns out to be a disastrous one since Nancy enters into it for all the wrong reasons. Her mother was on her way to try to prevent it when she was killed, and because of that Nancy blames herself for her mother's death.

At first Carl seems...