Early in the 1920s, the four McDonald brothers are performing in a carnival as a
stunt flying team, when they are hired by Mercury Airlines in
Newark, New Jersey, to haul the national
air mail for the US Air Mail Service. One of the brothers, Colin (
William Holden), instantly falls in love with Lucille Stewart (
Anne Baxter), the nurse giving him a physical. After less than a day, he proposes and she accepts. They marry and Colin starts flying for the company along the East Coast. Lucille soon becomes irritated by the brothers' extreme dedication to their work, but Colin promises that his efforts will make it possible for them to buy a home. When the youngest McDonald, Keith (
Johnny Sands), crashes his aircraft and dies, Ronald (
Sonny Tufts) feels guilty over causing his brother's death, since he was the one who taught him to fly. He quits the air and becomes a car salesman. When their friend and colleague "Porkie" (William Bendix) is fired for flying recklessly over a passenger train, he also turns to selling cars. The next brother to crash is Tad (
Sterling Hayden). Even though he survives, he is unable to fly again. Colin's former girlfriend, Poppy (
Jean Wallace), pays him a visit and tries to win him back, but he stays true to Lucille. Soon afterwards, their first child, a son, is born. Colin has promised to stop flying once he becomes a father, but when he is offered a raise by the company, he still continues to . During his first passenger flight, the wings ice over, and Colin crashes and dies. Colin's boss and Tad are the ones who have to break the news to Lucille, who is hosting their housewarming party. She decides to name her son Keith. ==Cast==