A young girl, Sadie Carr, disappears from a nightclub. That same night, Ronald Aitken, a long-term patient in a psychiatric hospital, escapes. In the early hours of the next morning, he is found high up in a tree, covered in blood, and holding Sadie's dead body, while the knife that killed her bears his fingerprints. A tragic case, but it seems cut and dried.
Sadie's father, John, is as devastated as her godmother, Commander Clare Blake. Blake appoints DCI Hedges and his number two, DS Brian Hall, to run the murder enquiry, and oversees the case herself. Her boss, DAC Edward Sumpter, is vocal in his opposition to her personal involvement but it looks as if it will all be wrapped up speedily. At the hospital, medical director Dr Miller reluctantly tells the police that Ronald murdered his mother eighteen years ago in a frenzied stabbing attack and hasn't spoken since.
The arrival of a Dutch policeman from Amsterdam, with details of three similar murders over there, muddies the waters. , Detective Inspector Van Hauten's edgy interaction with Hedges culminates in the two policemen having an embarrassing punch-up at Sadie's funeral. After reluctantly re-interviewing Sadie's boyfriend, Tony Leighton, Hedges is forced to concede that the deranged Ronald, who thinks he is a fruit bat, may not be the killer.
Traces of a date-rape drug have been found in Sadie's blood that could not have been administered by Ronald. The discovery of a second girl's body in the UK, who was killed before Sadie, when their suspect was securely locked up, makes it increasingly likely that the Ronald is actually a key witness to the murder of Blake's god-daughter.
DC Pamela Hayes is one of the local officers working on the case. She is the confidante of Helen Dirkwood, a civilian crime indexer at the police station where the murder team is based. Helen is convinced that her husband Carl is having an affair, maybe in Amsterdam where he often works, hiring and rigging nightclub lights with his nephew, Barry.
Carl and Barry have what seems an odd and unhealthy relationship, and Carl is sick of his older wife's jealous accusations. She starts to go through his pockets, looking for evidence of adultery but is faced with the even more unpalatable fact that her husband was in Amsterdam on the dates of some of the murders there. All the Dutch victims were last seen in nightclubs. And Carl is very wound up about a torn, stained black and green plaid jacket that she found at the back of their wardrobe and took to the dry cleaners. Helen doesn't know what to think.
Van Hauten makes an ally of Commander Blake, even managing to persuade her to let him cook her a meal, and stay overnight in her spare bedroom. However, Blake is increasingly convinced that he's hiding information from them, and her instinct is right. She finally gets Van Hauten to admit that he actually came over to London to see if he could trace what he suspects is the killer's van. He wants to catch the killer back in Holland, and the British police investigation is getting in his way.