In the summer of 1942, a unique and formidable unit of Canadian and American soldiers, known as the First Special Service Force, gathered in Helena, Montana, for rigorous training. Often composed of outcasts and those with a restless ambition, these men were forged into an aggressive, elite fighting force. Their training was brutal, designed to push them to their physical and mental limits, and they were prepared to face the unthinkable. The unit, later remembered as the Devil's Brigade, would go on to become one of the most effective and feared special forces units of the Second World War, leaving a trail of German corpses in their wake.