In nearly every police precinct, detectives are inevitably confronted with a case that goes unsolved. The more heinous the crime, the more it haunts those whose duty it is solve it. Such is the dilemma for Yohan Vivès—a young, recently promoted police Captain—when he begins investigating the gruesome murder of a young women named Clara in the town of Grenoble. It's clear that the attack was pre-meditated, and the violent nature of the crime suggests revenge. Vivés' team methodically digs through the details of Clara's life, uncovering her secrets in hopes of weeding out the killer. Certain their suspect is a scorned ex-lover, Vivés is confronted with another, more complicated question: which one?
