Karl Ludwig Schulmeister began as a smuggler on the Rhine border and ended up running espionage for Napoleon, and this film traces how that happened. Recruited as a double agent, he infiltrated Austrian command structures ahead of the 1805 campaign, feeding Vienna false intelligence while reporting troop movements back to French headquarters, work that historians here connect directly to the crushing French victory at Austerlitz and the collapse of the Third Coalition. The film follows his most audacious stunt, operating as acting chief of police in occupied Vienna while wanted as a fugitive under other names, relying on disguises and forged papers to move between identities. Historians and biographers walk through the surviving records and correspondence to weigh a question that still splits opinion in France and Austria alike: was Schulmeister a brilliant patriot serving his emperor, or a mercenary traitor who sold out his own country for money and status. Reenactments and period maps fill in the campaign context around the interviews.