Mr. Evers, a devoted father, nonetheless works hard to impose order and discipline on his brood of five children. When he discovers that his son Jack has borrowed his car without asking, he refuses to allow him to take the car for his date with Millicent Dayton that evening. Jack takes the car anyway, and Millicent teases him about his twelve-o'clock curfew. When she suggests a trip to a roadhouse, he refuses, and moments later, a policeman pulls them over and gives Jack a speeding ticket. The next Saturday night, Bonnie Evers and her boyfriend, Clark Newall, the son of a wealthy but absent father, go to a party and leave Jack, who is grounded, at home. Roger, another Evers boy and the family's moneylender, threatens to tell Mr. Evers about the speeding ticket if Jack doesn't pay back the money he had borrowed for his date with Millicent. That night, Bobby, the youngest Evers, accidentally cuts himself, and after Jack very adeptly treats the wound and saves Bobby's life, Roger generously forgets Jack's debt. At the party, a very bored Clark plays a ruse in order to leave. He initiates a game, "Charlie Chan at the Party," where, as the detective, he says that must leave the house with his four assistants: Bonnie, Millicent, his sister Patty and a friend, Jed Parker. At Clark's suggestion, the group goes to a nightclub where the Paxton Sisters perform. Bonnie worries about her curfew, and Clark, who has learned no scruples at home, begins to drink at the bar, concluding that his friends are a bore. The group decides to go home, and Clark offers to take a shortcut and to race Jed to Bonnie's house. Back at the Evers' home, Roger and Jack discuss ways of saving enough money to buy Millicent's brother Tom's car. Mr. Evers commends Jack on his heroic saving of Bobby and then, to Jack's surprise, offers to buy the car and also to raise Jack's allowance. A policeman arrives moments later and tells the family that Clark has been in an auto accident and that Bonnie is badly injured. The family rush to get ready to go to the hospital, but Bonnie arrives moments later unscathed, saying that she drove with Jed instead, and that Millicent had borrowed her coat before getting into Clark's car. Clark has also arrived at the Evers' house, and Mr. Evers calls Mr. Newall, who expresses anger rather than sympathy for Clark. When Newall arrives to pick up his son, Evers tells him that his neglectful parenting was at fault in Clark's accident. Seeing that he has not been a good father, Newall promises to treat Clark fairly and to use the accident as an opportunity to get closer to his son. Evers and Louise, his wife, look ahead wistfully to the many Saturday nights in their future.