An abandoned caboose becomes a junkie's hideout, a multiple murder has been committed. A police investigation leads nowhere, the crime remains unsolved, and Marceau, a hardened cop, resigns in the aftermath. But his troubles don't end there: someone is stalking him and his life is in danger. To save himself, Marceau recruits Camille, a young woman drummed out of the police academy for her inability to fire a gun. They make a pact: Camille agrees to flush out Marceau's potential murderer and Marceau, in exchange, undertakes to remunerate and train her. Camille plunges into Marceau's seedy underworld and encounters a raft of suspects. As Camille sinks deeper and deeper into this sordid world, she comes to terms with its violence and understands that the line between good and evil is narrow indeed. From this insight she draws the strength that had previously eluded her. Marceau's legacy... But who, exactly, is Marceau?