DCI Marcus Priestley is feeling bored with mundane police work. The presumed suicide of an artist is re-evaluated when a toxicology report suggests foul play. Priestley takes the case and sets about understanding art and artists, in order to apply his psychological approach to finding the perpetrator. He has dinner with beautiful art expert Anna, where she explains in some detail her unconventional views on modern art. She shows a personal interest in him, but Priestley is happily married and fully intends to remain so; nevertheless, he cannot avoid being attracted to her. Being a moral man,...

On Christmas Eve, DCI Marcus Priestley is aboard a Santa's Special at a heritage railway, with his wife Helen and their two children. The steam train is halted and a signalman is found dead. Helen, a doctor and psychiatrist, examines him and concludes he was murdered. Derbyshire police have the case taken off them by the Met, who rig an autopsy to conclude he died accidentally. Helen insists Marcus conduct his own unofficial investigation. He meets with the British Secret Intelligence Service and the CIA. When the suspect's phone is traced to Stockholm, he flies out with Lin Plummer, a DC....