Follows the story of two US Marines sent to learn from the British Commando training regime in Scotland, 1942.

Summer 1942. Defeatism hangs in the air. Britain stands alone. Winston Churchill is determined to strike back and has ordered the formation of a special operations force, dubbed "Commandos," with the mission to "set Europe ablaze."

U.S. Marine Captain Jim Cain and his Gunnery Sergeant Leland Montgomery are surprised to receive orders to the British Commando training center in the Scottish Highlands. There they are put through the brutal specialized training that will hone their fighting skills. Pitiless forced marches, dangerous live fire exercises and hazardous assault courses building their physical endurance, and a strong sense of brotherhood develops between the British soldiers and the two Marines. Lucky to be quartered in the spacious home of the Commandos' commanding officer, Cain has the pleasure of meeting his daughter, Loreena. Bright and stunning, Loreena is secretive about her work in London. Before Cain can learn more about her, the training course is interrupted and the commando squad is sent on a special mission to destroy a German radar station on Nazi-held Alderney, off the coast of France.

While the site is defended by a squad of second-rate garrison soldiers who are no match for the highly trained and motivated commandos, a reaction force of infantry, led by a German combat veteran, joins the fight. The action is fierce and bloody and there are heavy losses on both sides. The surviving raiders withdraw to Royal Navy motor torpedo boats, but a marauding squadron of Schnellboots (E-Boats) lies in wait.