As a bustling crowd clambers aboard the Great Western Railway excursion train, taking them to an illegal prize-fight in Berkshire, the train guard fears for the safety of his rolling stock. Little does he expect, however, the brutal murder of one of his passengers, Jake Bransby. On the shocking discovery of the body, Detective Inspector Robert Colbeck and his assistant, Sergeant Victor Leeming, are sent to the scene.

Faced with what initially appears to be a motiveless murder, Colbeck is intrigued by the murder weapon - a noose. When it emerges that Bransby has worked as a public executioner, he realises that this must be intrinsically linked to the killer`s choice of weapon. However, the further he delves into the case, the more mysterious it becomes. When a second man is strangled by a noose on a train, Colbeck knows that he must act quickly; can he catch the murderer before more lives are lost?