When a rare silver coffeepot in the shape of a locomotive disappears from the train to Cardiff and a murder subsequently occurs, Inspector Colbert and his sergeant are called in to investigate.

February 1918. Detective Inspector Harvey Marmion and Detective SergeantJoe Keedy are pulled from their beds to attend a sinister siege involving threeburglars where one policeman has already been shot dead. Attempts at talkingthe men in the house into surrender are met with stony silence so the policeproceed to batter down the door and Keedy bravely leads the way. A gunshotis heard. Keedy is hit.As Keedy is rushed to hospital, Marmion is on the trail...

1866. On a dark, brooding summer's evening, Agnes Lenham seats herself in an empty first-class compartment on the train to Portsmouth. She is joined by a naval officer and a middle-aged man, in high spirits after dining at his club, travelling to his home on the Isle of Wight. His name is Giles Blanchard - and within moments of the train leaving the station, the sailor strangles him... At Scotland Yard, Detective Inspector Colbeck and Sergeant Leeming...

When five female munitions workers on the home front are killed in a suspicious explosion, Marmion and Keedy must get to the bottom of who is responsible for such a horrendous act.