The nightmare began on a warm summer night. A six-year-old boy was found in a park shack, bludgeoned to death in the quiet residential district of Montreal's Notre-Dame-de-Grâce. Soon after, an eight-year-old boy disappeared. Horror and fear gripped the city. Neighbourhoods went silent. Suspects were questioned, suspicion and alarm mounts. No arrests were ever made.

When Lieutenant Detective Toni Damiano discovers the cold case many years later and learns that the three suspects are still alive, she's hooked, on what cops call a Detective's Case. Her partner, Detective Pierre Matte, hesitantly agrees to work with her. They meet Kathryn Flynn, the ninety-year-old mother, who has kept meticulous files throughout the years–her hope has never faltered. Damiano and Matte rediscover what binds them, a reckoning for the murderers among us and justice for the victims who have no voice.