David wants to go to a horror movie with his friends, but admits in embarrassment, "My mother won't let me." The boys go off to David's house to run his model racers, but the playroom is already occupied by his sister Sarah and a friend, who are practicing for a school play. The boys barge in and make fun of the girls. David and Sarah bait each other until their mother stops the quarreling by ordering the boys out. This angers David, who tells his friends that he will go to the horror movie anyway. Later that day Sarah asks David to help her hang a mobile in her room. As he grudgingly obliges, she asks whether he's coming to her play. He says that he has other plans, but that if she will stay out of the playroom for three weeks, he will come. Sarah agrees to accept the deal if he will tell her his plans. David makes her promise not to tell their mother and then reveals that he's going to the horror movie. When David leaves the movie the next afternoon, he suddenly realizes that he is late for Sarah's play. He rushes frantically to get to the school, only to catch sight of his mother standing outside with his sister. Because be hasn't made good on his part of the deal, he fears that Sarah will tell on him. At home Sarah expresses her hurt feelings by knocking around a doll that she pretends is her brother. Dav id shows up to ask anxiously whether she's told. "Maybe I did, and maybe I didn't," she answers. The two scuffle until their mother comes in to break up the fight, demanding that they explain their quarrel. Sarah now has her chance to tell . . . if she wants to take it.