In the winter of 1943, the Allied advance in Italy stalled against the formidable German defensive line known as the Gustav Line. A key obstacle was the mountain of La Difensa, which provided the German forces with a strategic vantage point to overlook the Liri Valley. To break the stalemate, the First Special Service Force, an elite unit of American and Canadian soldiers, was tasked with a daring and perilous mission to scale the mountain and dislodge the enemy. The operation, which required the men to climb the steep, rugged terrain under the cover of darkness, became one of the most challenging and significant battles of the Italian campaign.