In 1812 in Paris, Colonel Jean Doucet, the senior officer in the French army who controls an elite group of soldiers charged with protecting the city and stationed at strongholds throughout the city, holds Paris while Napoleon is off trying to bring down Russia. For months Doucet fulfills his duties without incident until October 23 when a strange man bursts into his office wearing a uniform and introduces himself as General Lamotte and presents a letter saying that Napolean is dead and that he has been named commandant of Paris by a provisional government. He claims to already have the support of several army garrisons and now demands that Doucet turns over command of his troops and surrender the capital.
During the summer, retired General Claude-Francoise de Malet (a former Musketeer and now a strict republican) believes that Napoleon is no better than a king and a first rate dictator. He hopes to restore democracy back to France. So he comes up with a plan to trick the government into thinking that Napoleon is dead. He forges a letter, puts on an old uniform and with his fake documents convinces senior military commanders to give him control of thousands of soldiers. But to take control of the government he needs the supports of the capitol's elite soldiers. When he arrives in Paris He has Colonel Gabriel Soulier arrest officers and releases some generals who were being held in prison who were cohorts of Malet. They then went on a spree of arresting others and putting their own men in office. He also shot the governor of Paris.
So he appears before Doucet with his letter saying that Napoleon had died on October 7. But Doucet had received a letter from Napoleon after that date and knew they were forged. Malet goes for his pistol, but Doucet is faster and Malet is arrested and put in jail. Malet is put before a firing squad. The coup very nearly worked and Napoleon rushes back from the front to secure his Empire only to be defeated ultimately by the English.