Richie is seated at a booth at Arnold's, and Al brings him a package containing his new plaid jacket to wear when playing with the band. Ralph and Potsie walk in wearing their jackets. Richie tries on his. Three leather-clad women walk into Arnold's. Richie sees "SHE DEVILS" on the back of their jackets and says that they must be a motorcycle gang. Lori Beth is gone for the weekend, and Richie says he's not going to chase after those girls. The girls say to themselves that the guys are exactly the kind of guys that Bertha told them to bring to the nerd party. The girls ask the guys to the party. One of the girls kisses Richie. Richie, Potsie, and Ralph walk into the party (being held in an abandoned beauty parlor) wearing their plaid jackets. Big Bertha meets the boys. She says that the She Devil who brings the most "interesting" date wins $100. Ralph introduces himself and tells a joke that doesn't go over well. Potsie begins to introduce himself, but Bertha cuts him off. Richie introduces himself and, based on the facts that he is a journalism major, lives at home, and eats meat loaf, is declared the winner. Another She Devil says she can find somebody better than Richie. Richie then tells the guys what he thinks is the reason for the She Devils party - to find the biggest nerd. Richie, Potsie, and Ralph are about to leave when some She Devils enter carrying somebody inside of a sack. Big Bertha says the guy jilted her kid sister and broke her heart. The guy is Chachi. Chachi tells the guys his story. Big Bertha says he dumped her kid sister, Rhonda. One of the She Devils chains Chachi's leg to a sink. Big Bertha puts the key in her shirt top. She invites Richie to come and get it if he's got the guts. Richie calls for a meeting with the guys. Bertha says they will shave Chachi's head at 9:00. Potsie and Ralph create a distraction so that Richie can escape to get Fonzie. Back at the house, Fonzie and the rest of the family are singing "Beer Barrel Polka" at the piano. Joanie chooses the song "By The Light Of The Silvery Moon" next. Richie arrives home and starts singing before talking to Fonzie in the kitchen about the nerd party. Fonzie tells Richie to stall them while he thinks of what to do. Back at the party, Bertha starts to shave Chachi's head when Richie pulls the plug. Richie puts the electric razor down his shirt, so Bertha tears his shirt off. Just before a fight between the guys and the She Devils is about to break out, the She Devil that left after Richie was declared the winner returns saying she's found a new winner. She brings in a snail collector named Artie (Fonzie). Artie pulls the sink out of the wall and he and the guys leave. Fonzie kicks the door in and puts the glasses and hat he was wearing on Big Bertha. At Arnold's, Richie tries to saw off the chain on Chachi's leg. Fonzie tells Chachi that what he did to Rhonda was low. At the house, the family sings a song at the piano.
Songs in this episode:
"Poison Ivy" by The Coasters (1959)
"Blueberry Hill" (instrumental) by Fats Domino (1956)
"Beer Barrel Polka" (sung by Fonzie, Howard, Marion, and Joanie) by The Andrew Sisters (1936)
"By The Light Of The Silvery Moon" (sung first by Fonzie, Howard, Marion, and Joanie, then by Richie, Howard, Marion, and Joanie, and lastly by Howard, Marion, and Joanie) by Bill Haydn (1912)
unknown sung (sung by the Cunninghams)