A sculptor, reluctant to join the war, becomes an ace flyer.
Sculptor Rocky Thorne (Richard Dix) loves Nancy Adams (Elizabeth Allan), and they plan to marry. Rocky calls American soldiers marching to war lemmings; but Nancy salutes them. Rocky objects to killing people; but Nancy calls him yellow and walks out.
Rocky joins the air corps and meets his squadron. Kelley (Theodore Newton) tells him not to think about the other guy. Captain Blake (Ralph Bellamy) orders reluctant Rocky not to make excuses. In air combat Rocky is wounded and shoots down a German plane. He complains about his plane, and Blake reprimands him for hesitating at first. Rocky's plane is shot and crash lands. Rocky knocks down the soldier who loaded his gun belts. A brother can't fly after his twin is killed, and he shoots himself. Rocky has a lion painted on his new airship. Blake won't let Rocky go up alone, but he does anyway.
In September 1918 Rocky shoots down several German planes. Nurse Nancy treats the wounded, who talk about Rocky and say he has shot down 28. They say Rocky is a lone wolf, and he has not written to Nancy. They are bombed, and Nancy screams. Nancy hears of Rocky's honors. He finds her on the street in Paris and gives her champagne. She wants to start over, and he kisses her. She tells Rocky that he has changed. He says he likes the war and wants to get drunk with her for 48 hours; she agrees.
A German cadet drops a letter about an American prisoner; but Rocky in the air shoots him down. Blake tells Rocky, who collapses. In the hospital Rocky tries to calm a delirious soldier, the one he shot down. Rocky helps him to die by giving him wine. Rocky asks Nancy why he forgot the answer he knew before. Lt. Col. Wentworth (Frank Conroy) asks Rocky to instruct new pilots; but Rocky learns that his record of 42 kills has been surpassed. Blake won't let Rocky fly alone; but Rocky disobeys. When he gets a German plane in his sight, he sees the cadet at the hospital and does not shoot. Rocky is hit, and his plane crashes. In the final scene Rocky limps along with Nancy and says that killing took away his birthright. Yet they plan to marry, and they kiss.
This strongly anti-war drama shows how a sensitive artist, who sees war as mass hysteria, is goaded into joining by his fiancé's patriotism. He is then transformed into the best of the war killers, though he eventually realizes that he has lost an important part of himself.