Brennan is called back to Montreal, Canada from teaching at the FBI Academy in Quantico when a biker gang war turns violent. Excavating at a biker clubhouse reveals the bones of a young girl from Myrtle Beach, South Carolina. Brennan has herself assigned to work with Operation Carcajou, a multijurisdictional task force created to investigate criminal activities among outlaw motorcycle gangs in the Province of Quebec. Her investigations are hampered by the lack of co-operation of Sergeant-Detective Luc Claudel, while would-be love interest Lieutenant-detective Andrew Ryan is unable to help due to being under investigation for corruption.
Meanwhile Brennan's teenage nephew Kit, having fallen out with his father and with his mother (Brennan's sister Harry) away, comes to stay and exhibits a worrying interest in Harley-Davidsons and their riders. Can Brennan find out how the girl's remains ended up in Montreal, help to bring the killers to justice, and keep Kit away from involvement with the biker gangs?