21 pilots die as a result of faulty cylinders made in the factory of Joe Keller and Steve Deever. We come to know that Steve Deever is in prison for the offence. Joe Keller, the boss, was sick and at home on the day when the cylinders were delivered. Joe Keller's elder son Larry Keller has been missing for a few years and now his second son Chris Keller wants to marry Larry's fiance, Ann, who is Steve Deever's daughter. George Deever, Ann's brother and Steve Deever's son is against the marriage. Quite early in the film we get the sense that somehow Joe Keller is the real culprit. Interestingly, the fact-finding is done by Chris, Joe Keller's own son, who first goes to meet Steve Deever in prison. Steve tells Chris that both Joe and Steve knew the cylinders were faulty. But on the day the cylinders were to be shipped, Joe chose to stay at home and convinced Steve to ship the cylinders by asserting that if there was an issue, he, ie Joe would take the blame. In the court, Joe denies any knowledge that the cylinders were faulty and Steve is imprisoned for the crime. Eventually, Joe realises his folly and commits suicide saying, 'They were all my sons'. Kate Keller, Joe's wife and Chris's mother, sends off Chris and Ann with the message that let bygones be bygones and to make a new beginning.