Marion and Joanie are putting plates on the table and are arguing about something. Howard comes home with Chachi. Marion asks Howard to tell Joanie that she can't do that. Howard doesn't know what she is talking about. Joanie explains that she has been accepted to a special teacher's assistant program. Howard is happy about it, but when Joanie says that she is going to be teaching at George S. Patton Vocational High School, he isn't so happy anymore. Marion still tries to stop Joanie from going there. Howard escapes the argument by going upstairs. Joanie asks Chachi's opinion, and Chachi agrees with Marion. Joanie threatens to move to Jenny Piccalo's place at the Marine base. Fonzie comes in through the kitchen and into the living room with Chachi. Joanie is about to leave the house, but Fonzie stops her and asks what's the matter. Marion explains it to Fonzie, and he says that he already knows about it. Fonzie asks Joanie to sit while he calls Howard back downstairs. Fonzie explains that he will take good care of Joanie and that everybody should encourage her for doing what she is doing. Marion still disagrees. Howard thinks that Joanie should make her own decisions. Marion finally agrees, and they make up.
The next morning, Marion yells at Joanie to come downstairs so that she won't be late. Joanie comes down and asks how she looks. Marion tells her that she looks really good. Howard tries to give Joanie a roll of quarters to use as protection, but she declines. When Joanie is about to leave the house, Marion gives her her lunch and a roll of quarters. Joanie says that she isn't going to hit anybody, and Marion explains that it's her milk money.
At Patton, the students are throwing objects at Mrs. Shellenback. Fonzie is escorting Joanie to that classroom, and, when they get there, he introduces Joanie to Mrs. Shellenback. Fonzie advises the class to behave and, then, leaves. Mrs. Shellenback says that she is leaving for a short break, but as she is leaving, she drops an airline ticket. It's Wednesday, and Mrs. Shellenback won't be back until Monday. Joanie picks them up and hands them over to Mrs. Shellenback. Mrs. Shellenback leaves the class. Joanie asks for the seating chart, and the students say that it's in the right drawer. Joanie opens it and out fly novelty springing snakes. Joanie asks what they were doing before she arrived, and somebody says that Joey was reading. Joanie asks if he could continue, and Joey starts to read from an erotic novel. Joanie asks him to stop. Frankie, one of the students, takes the book from Joey. Joanie starts to give everybody their homework assignment, and the students begin to leave. Joanie calls them back. She says that she is available if anybody needs extra help. The bell rings, and everybody except Frankie leaves. Frankie asks for help from Joanie, and she agrees. Joanie leaves the classroom.
Later that night, Howard is thanking Chachi for taking Potsie's place when they go bowling. Howard asks Joanie to come as well, but she has lesson plans to take care of. The doorbell rings, and Howard answers it. Frankie comes in carrying a pizza. Joanie is wondering what Frankie is doing there. Frankie explains that he wants help from her now. Chachi, Howard, and Marion don't like what they see. Chachi calls a family meeting in the kitchen. Chachi says to Joanie that guys like that only have one thing on their mind. Howard and Marion agree with Chachi. Joanie leaves the kitchen to go to the living room, and the others follow. Howard, Marion, and Chachi leave. Frankie starts to harass Joanie, and, all of a sudden, Chachi comes back (he forgot something) and sees what Frankie is doing. Chachi kicks Frankie out. Chachi and Joanie discuss it, and Joanie says that she can handle it. Joanie goes upstairs.
The next day, at Patton, Joanie asks the class to hand in their book reports. Frankie asks if he can help, and Joanie says she thinks she can handle it. Joanie asks who hasn't done their homework because she only has three papers in her hand, and there are four students in the row. Joanie asks the boy who is sitting in the back to hand in his paper (the boy is Chachi in disguise). Joanie recognizes Chachi and asks him to step aside for a talk. Joanie is wondering what Chachi is doing there, and he says that he is looking after her. Joanie asks Chachi to leave. The minute she says that, a closet door opens, and Howard steps out and leaves the class. Chachi follows him. Joanie continues to teach until the fire alarm goes off. All of the students leave except Frankie who locks the doors, closes the blinds, and starts to harass Joanie again. She screams for help, and Fonzie kicks the door open. After Fonzie threatens him, Frankie jumps out the window. Fonzie comforts Joanie. Joanie thinks that she has failed as a teacher, but Fonzie doesn't think so and tells her why. Fonzie and Joanie leave the class.