June 1812. Napoleon Bonaparte begins his invasion of Russia leading the largest army Europe has ever seen. But amongst the troops of the Grande Armée is a savage murderer whose bloodlust is not satisfied in battle. When a Polish woman is brutally stabbed, Captain Quentin Margont of the eighty-forth regiment is put in charge of an investigation to unmask the perpetrator. Armed with the fact that the killer is an officer, Margont knows that he faces an impossible task and the greatest challenge of his military career