In World War I France, Lt. Jean Herbillion [Louis Hayward] sits in a Paris theater when a woman who goes by Denise [Miriam Hopkins] sits beside him. The performance is interrupted by an air raid and the theatre empties in a panic, but Denise is knocked out in the commotion, and Jean stays with her in the orchestra pit until she comes to. They spend the evening together, and he reveals he is hours from joining a squadron. Denise agrees to meet him at his morning train; as they exchange mailing addresses, she cautions him to mail her by General Delivery as she claims to be moving, and when he mentions his division, she seems to recognize it but does not let on.
Arriving at the squadron, Jean finds a group of upbeat, patriotic men eager to fly. But their top fighter pilot Lt. Claude Maury [Paul Muni] has a reputation for taking dangerous, lone-wolf missions and often returns to base with observers killed or wounded. Some call him cursed or dangerous, and only Jean volunteers to fly with him as his observer/gunner. The two men grow close, each sharing the names of the women they are fighting to stay alive for.
When Jean is granted leave to return to Paris, Claude hands him a letter to deliver to his wife. At the address, Jean discovers Denise is actually his wife Helene Maury [Miriam Hopkins]. Helene explains that she loves Jean but feels loyalty to her husband, while lamenting Claude’s near-suicidal behavior in combat. Jean is horrified at the idea of betraying his best friend and superior officer, and cuts off contact with Denise, which also strains his relationship with Claude.
Helene learns the squadron will have an extended stay in a nearby city and tells Claude, though not Jean, about her plan to visit. Jean tries to foster a relationship with Florence [Mady Christians], a saloon girl, and a confrontation with Florence’s former boyfriend leads Claude to discipline him. Jean attempts to avoid Helene during her visit, but they meet in a church and reaffirm their passion. Helene learns the squadron is unexpectedly summoned for a battle, and the high command seeks a volunteer to stay in Paris to train more pilots. She informs Jean of the offer and he volunteers, which arouses Claude’s suspicions since he was the one who told her about it. Captain Thelis [Colin Clive] steps in and urges Jean to stay, warning him the other men will think him a coward, so he remains with the squad.
On the eve of a major dogfight, Claude confronts Jean and asks if he has had an affair with his wife, but Jean denies it. They take to the skies and down several enemy fighters, but upon returning, Jean is killed and Claude is badly wounded. Claude finds a signed photo of Jean and Helene together that he, in his dying moments, was trying to tear up. In the hospital, Helene tends to the recovering Claude, and they are visited by Jean’s young brother Georges [Wally Albright]. The boy asks for details about Jean’s last moments, and Claude tells him that Jean died calling for his mother and Georges, then confesses he lied, saying Jean cried out for his true love, Denise, leaving Helene to cope with the truth as she nurses him back to health.
