On the day of his graduation from the police academy, Antoine (Lespert) learns that his request for assignment in Paris has been granted. While his wife remains in the country, Antoine finds a place in town and starts working in the criminal unit run by Inspector Caroline Vaudieu (Baye), who's recovering from a long battle with alcoholism brought on by the death of her son. The police unit becomes a kind of refuge for them both, as Antoine pours himself into his work and Caroline fights to regain the respect she'd lost. Investigating a series of brutal attacks along the banks of the Seine, they begin to form a unique bond - until tragedy strikes and sends them both hurtling to the edge.