Audrey Favreau's dead body is found in her apartment on a freezing winter morning. For detectives Valérie Laforge and Sam Barbieri, this case doesn't need further investigation: all the evidence points to Antoine, the victim's fiancé. But Antoine has a twin brother, Tom, who looks like him - like two peas in a pod. Dealing with this toxic relationship, and the relocation of their police station, Laforge and Barbieri have to go beyond appearances and defeat their own demons to find the true murderer.