Prior to the Normandy landings, former Merchant Marines Mason and Corliss are among three new recruits that are assigned to the 1st Platoon, "D" Company, 502nd Parachute Infantry Regiment, the other being Talbot. Mason gets off on the wrong foot with certain members of the platoon, mainly Sgt. Forrest and Cpl. Dreef. Mason gets drunk as he reads a Dear John letter from his girlfriend back home. The platoon's passes into town are canceled due to a stand-by for the invasion and are restricted to barracks. When the platoon returns to the barracks, they find it destroyed by a drunken Mason. Platoon Leader Lt. Pauling decides to keep Mason in the platoon and give him a chance, despite his behavior. Lt. Pauling talks to the platoon about Mason's behavior and Corliss speaks positively about him. The men decide to take a chance on him, including Grimes, Dubrowski, and Foley. The 502nd find themselves boarding troop planes that will be flying over Normandy, marking the beginning of the Normandy Invasion. Peterson begins to suffer from air sickness as a result of forgetting to take his air sickness pills. Sgt. Forrest is the jumpmaster for the platoon's plane and he gives directions on what to do when preparing to jump and what to do on the ground. The platoon is tasked to set up roadblocks and hold a bridge along the Douve, with their drop zone being a mile beyond 2nd Battalion's. Only seconds after the planes fly over the coast the Germans man anti-aircraft cannons and aim them towards the formation of planes. Peterson is killed when flak hits the platoon's plane. After the men jump out of the aircraft they realize that they did not land in their assigned drop zone but create a rallying point. The platoon heads out and Lt. Pauling gives out the order to not engage the enemy single-handedly. The men decide to split up into three groups and they scout the area. Mason sees a German sentry aiming his rifle at Cpl. Dreef and kills the sentry, which results in a firefight that ends with Cpl. Dreef getting killed. Not having seen what Mason did, the others blame him for a hotheaded stunt. After the platoon meets back at their rallying point, the platoon is outraged when Dubrowski tells them what happened. A German soldier fires at Lt. Pauling, the bullet flash burning him. Sgt. Forrest selects Mason to take care of Lt. Pauling, who is now suffering from blindness. The platoon decides to attack a German-infested farmhouse later that morning, resulting in the deaths of Lambert, Hernandez, and Nolan. After the firefight, the platoon raids the house, finding a German soldier by the name of Hans Schacht holding a French girl named Marianne hostage. Hans is taken prisoner and Marianne volunteers to aid Lt. Pauling. Hans informs the platoon that there are 300 German soldiers between them and the Douve. The platoon hijacks a German truck and forces the driver to take them to a tavern that is being used as a German headquarters. At gunpoint, Hans telephones false orders that draw German troops away from their positions. But then he seizes a chance to telephone again so the Germans can hear the platoon chattering in English. A truckload of Germans raid the tavern. Hans is killed by friendly fire. Talbot, Foley, Smith, and Torren are killed while Mason is wounded in his arm. The seven surviving members of the party escape by truck. By midday the party links up with the rest of "D" Company at the very bridge that they were supposed to hold. Lt. Pauling bids a farewell to Marianne before he and Mason are driven to a field hospital.
Parts of the film were filmed at Fort Benning, Georgia. The technical advisers were Richard Haynes Case, a D-Day veteran of the 101st and Werner Klingler, a German film director who also had a role in the film. Case had also acted as an adviser to The Man in the Gray Flannel Suit in the same year. Jan Merlin recalled that originally he was supposed to play Private Mason due to his reputation for playing villains. As his character was to continually carry the blinded Lieutenant who was to have been played by the much taller Tom Tryon, the two agreed to switch their roles to make things easier. As Tryon usually played heroes he welcomed the change in roles.
