In 15 BC, Roman legions under Emperor Augustus advanced into the Alps to secure the route to Germania. Research in Graubünden uncovered an ancient battlefield: remains of battles between Romans and Celts, and the highest military camp of the Roman Empire at 2,300 meters. The film follows archaeologists, forensics experts, and ballistics specialists in reconstructing the campaign. A key weapon was the sling, with deadly lead projectiles. Despite extreme challenges, the Romans conquered large parts of the Alps in one summer, integrating them into the province of Raetia for 400 years.
