Sergeant-Detective Émile Cinq-Mars fails with a task set to him by his former captain and the consequences look set to spark a gangland war in Montreal.

Montreal, 1978. Newly promoted Sergeant-Detective Émile Cinq-Mars attends the scene of seventeen break-ins at an apartment complex. Nothing more than stolen toasters. Cinq-Mars suspects that the burglaries are a trial run for a bigger heist . . . until he discovers a body pinned to a wall with a machete in one apartment.

When the former captain of Night Patrol, Armand Touton, receives a tip from an undercover informant in the Mafia, Cinq-Mars is ordered to intervene with a prisoner's release: the man must stay behind bars. He fails with the task and the immediate consequences are devastating.

While trying to remedy his failure, and also solve the mystery of the break-ins and the case of the dead body, a chilling aspect emerges . . . gangland Montreal is bracing for war.