In June 1812, Napoleon begins his invasion of Russia leading the largest army the world has ever seen. But amongst the troops of the Grande Armee is a savage murderer whose bloodlust is not satisfied in battle. When an innocent Polish woman is fatally stabbed, Captain Quentin Margont of the 84th regiment is put in charge of a secret investigation to unmask the perpetrator. Armed with the sole fact that the killer is an officer, Margont knows that he faces a near-impossible task and the greatest challenge of his military career.