Alex Cross, a psychologist and police detective, is called to a crime scene where a mother, her daughter and her toddler son were murdered.

Alex and John arrive at the children's school to discover not only fellow officers from the Washington, D.C., police department, but the Secret Service and the FBI.

Annoyed that more attention is being devoted to this high-profile case than to the Sanders-family murders in the poor neighborhood of Washington Southeast, Alex arrives at the crime scene with the intention of getting out of the investigation.

While there, they receive another demand and decide to follow the instructions in the hopes of saving the other child victim, Maggie Rose Dunne.

Eventually, a teacher from the child victims' school is found murdered in the same manner as the Sanders women, and Maggie's shoe is left at the crime scene.

The suspect claims to have a dissociative identity disorder, and Alex convinces those in charge to allow him to hypnotize Gary in order to determine if he is telling the truth.

Gary Soneji insists he was being watched before the kidnappings, including the night he murdered the Sanders family, supporting an eyewitness statement.

Alex connects Gary Soneji's story of being watched to the Secret Service agents assigned to Michael Goldberg and goes to the FBI with his theory.

The FBI confirms Alex's suspicions and believes that Jezzie Flanagan, the Secret Service supervisor, was involved due to her sexual relationship with one of the agents.

Flanagan is arrested based on a recording Sampson made of the conversation, and Maggie Rose is found with a native Bolivian family near the Andes Mountains, where she had been living for the past two years.

A film adaptation of the same name was released on April 6, 2001, starring Morgan Freeman as Alex Cross, Monica Potter as Jezzie Flanagan, and Michael Wincott as Gary Soneji.