When a severed head is left on the steps of Newgate Prison, Lord Redmond and Inspector Haze are left with few clues to solve the murder. Even after the victim is identified as the prison's hangman, narrowing down the number of suspects proves difficult when the victim was responsible for dozens of deaths, leaving a long list of relatives who might have wanted revenge.

Jason and Daniel must delve into the grim world of a career hangman in order to discover who had loathed him enough to perform an execution of their own.