Stationed in Scotland, Maj. William Darby and the men under his command are trained by British commandos, becoming the U.S. Army's 1st Ranger Battalion. Their drilling period is rigorous, but the men find time to romance local women before being deployed to fight the Nazis. U.S. forces battle from French North Africa to Italy, but when a surprise attack decimates the 1st and 3rd Battalions at the Battle of Cisterna, Darby and the 4th Battalion must come to their aid.
