Bobby, Peter and Alice are making a dunking booth for the school carnival. Then Greg comes home in a temper because the coach took him off the first-string basketball team and replaced him with Warren Mulaney. What makes Greg even more angry is that Warren also beat him for the position of student council president by making phoney he did not keep. He says Warren got his place on the team with by buttering up the coach but goofs off when the coach is not looking. Mike tries to reassure Greg that the coach will find out.
Meanwhile, Marcia is all excited because a boy from high school asked her out on a date to the pizza parlor. And the boy is none other than Warren Mulaney. When Marcia finds out about how Greg feels about Warren, she realizes she is a quandary. She asks her mother for advice, and she says it is really Greg's problem. But Marcia is still worried and, with the help of Alice, tries to keep Greg and Warren apart when Warren comes over. But Greg sees Warren anyway and is furious. The intervention of Carol and Mike keeps things from getting ugly.
When Marcia returns from her date she says she did not find Warren all that great and she does not want to upset Greg any further by dating him. But before she can tell Greg, he calls her "Benedict Arnold" angrily tells her not to date Warren or there will be trouble. This rubs Marcia up the wrong way and she continues to date Warren to annoy Greg. Meanwhile, the dunking booth, dubbed "Brady Booth" is finished and the younger kids are eagerly trying it out.
Greg hits back at Marcia by dating the girl who beat her at cheerleading, Kathy Lawrence. When Jan tells Marcia, she is furious, but takes the cunning tactic of not letting it bother her. When Kathy arrives, Marcia acts politely and friendly and concentrates on her homework with Warren. Greg tries to infuriate Marcia by having Kathy practice her cheerleading in earshot of Marcia. Marcia comes and makes snide remarks about the basketball team. This really angers Greg, and he and Marcia go out to have an argument. The younger kids are enjoying the show through the window.
But then the parents come home and ask what the attraction is. The kids tell them Greg and Marcia invited Warren and Kathy over for the purpose of bugging each other. The parents tell Marcia and Greg that they have not only been behaving badly but have used other people to do it, and been very selfish and unfair to them. Marcia and Greg realize what they have done and are sorry. Mike orders them to tell this to Kathy and Warren.
Outside, Alice is collecting towels off the dunking booth when she decides to try out the dunking machine. Just as she is about to do so, Greg and Marcia ask where Warren and Kathy are. Alice tells them that Kathy and Warren have hit it off and they have gone to the pizza parlor. Marcia and Greg are delighted for them, but still have to apologize. They go down the pizza parlor to do so. When they are gone, Alice (accidentally) dunks herself, but enjoys it.
The Bradys come home from a great carnival with goldfish, balloons and other prizes. Alice, who has her hands tucked under her coat, says her only prize was a pair of trick handcuffs. When the others are gone, Alice removes the coat to reveal that her hands are locked in the cuffs.