While on a lecture tour of Hong Kong, criminal psychologist Fitz is called in to investigate the murder of a high-flying business man and the disappearance of a young Chinese girl.
Dr Fitzgerald, returns to England after 10 years in Australia, for his daughter's wedding, he is soon investigating a murder case, involving a British soldier.
A prostitute has been brutally murdered, and the police believe they have found the murderer. Fitz, DS Jimmy Beck, and DS Jane Penhaligon are assigned to work on the case. While their suspect is in custody, a second identical murder takes place. They believe a confidant of the suspect has committed the second murder in order to clear his name. They question the suspect's wife and brother, but meanwhile, a third identical murder takes place. Fitz is visited by his brother, who tells him their mother has died.
The autopsy of the prostitute Joyce Watkins reveals that she was killed in the same manner as Jean McIlvanney, and forensic evidence links David Harvey to both crimes - yet when the second was committed he was behind bars. Fitz suspects that David's brother, the priest Michael Harvey, is involved. He visits Maggie Harvey who tells them that Michael visits prostitutes. Michael denies the murders and accuses Maggie of the second murder. While Michael takes Fitz's mother's funeral, Maggie visits some local prostitutes, finds out her husband used one of them, and kills her. As the police investigate, Fitz rushes to the hospital, as Judith has gone into labour.
In a bid to trap the murderer, Penhaligon and a colleague go undercover as prostitutes and start walking the red light district. Meanwhle, in the local pub, Jimmy Beck breaks down and confesses to the rape of Penhaligon. Fitz does not betray Beck's trust. Fitz is sure that Maggie is the murderer. Maggie visits another prostitute her husband has used, and Beck rushes in to save the prostitute. Under questionning, Maggie confesses to the murders, and the police have no evidence on which to charge her husband, David, and they have to let him go. Beck takes the law into his own hands to get a confession from him. In a dramatic rooftop scene, Beck finally faces Penhaligon.
Bill Nash, a young man who was brought up in care, is picked on at his job in a factory. Stuart Grady, the foreman, takes him under his wing. When Bill is locked out of his home, Grady takes him back to his flat. The next day, Grady's landlady comes to collect the rent, assumes the two are lovers, and threatens to throw them out. Bill stabs her, Grady finishes her off, and they dispose of the body in the basement. The landlady's husband returns home finds the body, and calls the police. Fitz at first believes the husband is guilty, and Bill and Grady go on the run. They come across Bill's foster family, and follow them home. The family calls his social worker, and when he confronts the two of them, Bill reacts violently.
The police examine the body of social worker Ian McVerry, and the two murderers are still on the run. Fitz and the police find out his last appointment was with the Nash family and discover the connection with Bill. Meanwhile, Bill and Grady decide to burn the car, but Bill burns his leg. They go to hospital, but realise the police have been informed. Grady is captured, but Bill is still on the run. The police track him down to the disused factory, and take Grady with them to try to talk him into handing over the gun.
Fitz receives anonymous love letters while investigating the murder of a male psychology student, who was electrocuted following consenting sex. The killer left a message in the form of a tape recording of a Dusty Springfield song.
The police mount a campaign to find the murderer, but meanwhile she seduces Fitz's son, Mark, and takes him back to her flat. Fitz receives a fax informing him that Mark has been kidnapped and the race is on to find him. The police find her address, and she is waiting for them. Fitz interrogates her, finds out why she craves attention, and tries to locate his son.
