In an English military training camp in mid-1940, Canadian Steve "Canada" McKendrick begins the grueling regime of training as a parachutist under his new commanding officer, Major Snow. The night before the men's first group jump from a balloon, several men nervously study their training manual and learn that a "Roman candle" is the term used to describe a parachute that fails to open. Canada piques the men's interest by admitting to having witnessed a Roman candle. The following morning a superstitious Canada exchanges his chute with packer Penny Gardner and makes the first jump successfully. Canada then asks Penny for a date, but when she overhears him threaten drill instructor Sgt. Breton, she refuses. The next day the men leave on their first airborne flight, and when none volunteer to be the first one off, Breton cheerfully jumps, only to "Roman candle" as the men watch, horrified. The trainee in command quickly recovers and forces the men to make their jumps. That night, several men toast Breton, but when Corp. Dawes mocks America's Lend-Lease program, Canada instigates a brawl, while Penny watches, dismayed. When brought before Snow, both Dawes and Canada admit to beginning the row and escape punishment. Curious about Canada's barely concealed rage, Snow orders a private investigation into his past. The men continue their training and after several weeks earn their wings. Shortly afterward, Snow hand-picks a group, including Canada, for Operation Pegasus, whose objective is a vital radar site inside Germany. Before take-off, Canada gets his chute from Penny, but is indifferent when she reads him the "Packer's Prayer," a verse reflecting the packer's unique involvement with each operation. On board, Canada finds a small handkerchief tucked into his chute. Upon landing, Dawes breaks both legs, but despite continual enemy fire, the mission is successful and the men are picked up safely by a naval cruiser. Canada visits Dawes at the base infirmary and discovers that both of his legs have been amputated. Canada waves Penny away when she notices his concern and angrily tries to return the handkerchief, which she explains is only a good luck custom. The men choose a red beret as their unit emblem, which becomes part of their uniforms. Snow summons Canada and offers him a commission, which Canada flatly refuses, insisting on remaining a private. Later, the base receives several Dakota airplanes from the U.S., flown by American pilots, one of whom claims to recognize Canada. Penny invites Canada to her parents's home in the country and prods him into revealing his past. He admits to having served as an officer in the U.S. Army as a test pilot. He remains guilt-ridden over the death of his best friend, whom Canada forced to jump from a damaged plane, then watched him "Roman candle." Penny reassures Canada that he did the right thing and encourages him to take the commission offered by Snow, but he again declines. Snow summons Canada and repeats his commission offer, acknowledging that he knows about Canada's past service. Canada turns down the offer and demands a transfer, which Snow denies. Believing Penny has informed Snow, Canada upbraids her, but when she maintains her innocence, they quarrel. With news of the Allied invasion of North Africa, the Red Beret unit is ordered to jump into Tunis to support the landing forces. On the morning of the mission, Canada, still angry, initially rejects Penny's chute, but when he is refused another from the other packer, grudgingly accepts it. Before boarding his craft he finds another handkerchief tucked in the chute and waves a pleased acknowledgment to Penny. The men, now calm and relaxed about jumping, make a successful landing, despite heavy enemy attacks. In the desert, the outfit evades a German tank division and fights its way through a road block only to find themselves in a minefield. Both Snow and the sergeant major are wounded. As a German officer makes a surrender demand, Canada discovers they are carrying a bazooka and ammunition and suggests to Snow that a safe path might be blown through the minefield. Snow orders Canada to take command and lead the men to safety and after some hesitation, Canada proceeds. The segeant major dies before the evacuation is completed, but the unit meets up with the invasion force as planned. Snow presents Canada with the transfer he had requested earlier, but Canada refuses and instead asks for another chance at the officer commission.