All My Sons recap

Several years after the war, manufacturer Joe Keller lives comfortably after being cleared in a case involving defective aircraft parts; his partner Steve Deever remains in prison. Joe's son Chris plans to marry Steve's daughter Ann, once engaged to Chris's missing brother Larry, while Kate Keller insists Larry is alive. Ann's brother George arrives convinced Joe ordered Steve to ship the parts. Kate accidentally undermines Joe's alibi, and Joe admits to Chris that he gave the order to protect the business, though twenty-one pilots died. Ann then produces Larry's final letter, which reveals that he intended to die after learning of his father's crime. Joe recognizes that his obligation included the dead pilots, not only his own family. He goes inside and shoots himself. Kate tells the devastated Chris to leave with Ann and live rather than carry Joe's guilt.

In the Keller family's backyard several years after the war, a storm has snapped the memorial tree planted for their missing son Larry. Joe Keller, a successful manufacturer, was cleared after his factory shipped cracked aircraft cylinder heads that contributed to twenty-one pilots' deaths; his former partner Steve Deever remains imprisoned. Joe's surviving son Chris wants to marry Steve's daughter Ann, who was Larry's sweetheart before he disappeared. Kate Keller still believes Larry will return and treats the broken tree as a sign, so Chris knows the marriage will force a reckoning. Ann says she no longer waits for Larry and returns Chris's love. Neighbors visit, revealing the family's comfortable place in the community but also lingering doubts about the factory case. Ann's brother George, a lawyer, calls after visiting Steve in prison and says he is coming immediately. His urgency suggests that the old verdict and the proposed marriage cannot remain separate.

As Chris and Ann prepare to announce their engagement, neighbor Sue Bayliss tells Ann that people still suspect Joe and resent the moral idealism Chris can afford through the factory's profits. George arrives after hearing Steve's account: during the wartime rush, Steve found defects in a batch of cylinder heads and telephoned Joe, who ordered him to weld and ship them. Joe insists he was home sick and that Steve acted alone. The old neighborhood's warmth briefly weakens George's resolve, but Kate casually says Joe has not been ill in many years, contradicting the alibi on which his acquittal depended. George leaves with his suspicions confirmed. Chris confronts his father. Joe admits that he told Steve to ship the parts because he feared losing government contracts and the business he meant to leave his sons. He claims he expected the military to catch the defective batch before use. Chris, appalled that Joe placed the business above the pilots' lives and then let Steve take the punishment, leaves the house in anguish.

Kate understands that admitting Larry's death would also expose the connection between Joe's crime and their son's fate: if Larry died in the war, Joe helped destroy men like him. Chris returns without the resolve to report Joe, but he can no longer respect his father or accept the life the factory financed. Ann wants Kate to release Chris from Larry's memory and produces a letter Larry sent her on the day he vanished. After learning about the defective parts, Larry wrote that he could not bear his father's responsibility and intended not to return from his mission. Joe reads the letter and finally grasps that duty cannot stop at the boundary of his own family; the dead pilots were also his sons in the larger human sense. He goes inside, saying he will get ready to surrender, and shoots himself. Chris blames himself for pressing the truth to its conclusion, but Kate tells him not to carry the guilt and urges him to leave with Ann and live.

Ann shows Kate a letter Larry wrote before his final flight. Larry had learned of the defective engine parts and said that shame over his father's actions had made him decide not to return alive. Chris no longer intends to send Joe to prison, but his disillusionment leaves the family without a moral way forward. When Joe reads Larry's letter, he finally accepts a responsibility extending beyond his household: the pilots who died were also, in a human sense, his sons. He goes inside, apparently to prepare to surrender, and shoots himself. Chris is overcome by guilt for forcing the confrontation. Kate, after years of preserving the family's denials, tells him not to blame himself and urges him to go on living with Ann. Joe is dead, Larry's fate is confirmed as suicide, and the family business and the future Joe built around it are morally shattered.