London is being terrorized by a mysterious killer taking the guise of the "Brick Man", a mythical figure from London folklore who comes out of brick walls on Brick Night and stabs people - except this time its real and people are dying.
Rabbit is excluded from his team's undercover investigation of youth gangs and sent to investigate a series of deaths at and old people's home, leading to him questioning if he is getting too old for police work.
A mystery sniper is killing in London, and Rabbit has to protect a visiting Prince of Bulgaria. He also deals with the Prince's sister, his old sniper flame, and UK's latest novelty - the telephone. Lydia grooms Mabel for her organization.
When a seemingly mad poisoner takes a group of young women hostage and threatens to release deadly gas if the police storms in, Rabbit must resolve the crisis before the female con he loves is executed for her crimes.