[1] It is the ninth in his series of novels featuring Inspector French, a prominent figure of the Golden Age of Detective Fiction.

One evening one of the employees, a young engineer named Ronnie Ackerley is run over by a train on the route.

The inquest initially considers it an accident, but subsequent information leads the local police to call in the assistance of Scotland Yard.

A major scheme to defraud the railway company is also exposed, leading one of the employees to inflate the amount of work being done and pocket the difference.

The death is deemed a suicide and Carey is held responsible for both the fraud and for murdering Ackerley who was on the trail of uncovering it.