Over breakfast, Bill Fry tells his wife Constance that he has had another call from their old friend, Dan Carter, who is the principal at their overly imaginative teenage son Junior's school. When Junior comes to the table, Bill reproaches him for making up wild stories about Dan, whom the boy believes to be at the center of a widespread conspiracy. After Bill drives his son to school, Junior discovers that his father's pistol has fallen out of the car. Junior puts the gun in his pocket, but as he and his buddy Horace are sneaking into the school through an air vent, the gun falls out of his pocket and discharges. When the police show up, Junior, who suspects that Dan used his father's gun, suggests that they have ballistics compare the gun's bullets with a slug retrieved at the unsolved Midvale Bank robbery fifteen years before. The police ask for more information about the robbery, and when they encourage the boy to use his imagination, Junior enthusiastically begins his story: On a stormy night in Midvale, a criminal robs the bank and kills the teller, then flees with the police in pursuit. The next day, Constance Denning swerves to avoid a telephone company truck stopped in the middle of the road, and her car gets stuck in the mud. Bill, the lineman, agrees to drive her to the bus stop so she can continue on her way to Los Angeles to get married. When Constance misses her bus, she and Bill quarrel, and she is about to set out on foot when the bank robber emerges from the back of the truck and takes them hostage. The radiator bursts, and while the truck is stopped, they encounter Cudgeons, a mousy necktie salesman. The robber sends Cudgeons away, and as he and his hostages search for shelter, the attraction between Bill and Constance grows. They eventually reach the Petrucci winery, where they are given shelter for the night, and Bill admits that he could have stopped Constance's bus if he had wanted to. In the middle of the night, Constance sneaks out the window, climbs the telephone pole and uses Bill's handset to tap into a line. After calling her fiance to break off their engagement, she attempts to contact the police, but the robber wakes up and shoots at them before escaping through the winery. Back at Junior's school, the boy is near the end of his story when a policeman brings the news that Bill's gun was the one used in the robbery. Junior continues to cast suspicion on his principal, and the police bring in Cudgeons, who agrees with Junior's account of the long-past events. That evening, Bill and Constance learn that Dan is in jail, and when they go to see him, they are promptly locked up as well. Junior suddenly gets an idea and runs off to crack the case. He and Horace break into Cudgeons' home and call out from the darkness, urging Cudgeons to give himself up. Just as Cudgeons grabs a gun and traps the boys, the police step in to seize him. Junior's heroic deed makes the front page, and the boy confesses that he first suspected Cudgeons because he was the only person who actually believed his story. Junior then looks on in amusement as his parents begin to tell their friends greatly exaggerated versions of his exploits.
