Kotter's father travels 1,400 miles to see him and to see what he does at school. While the senior Kotter observes his son teaching about the Great Depression, he tries to take over the class and tell stories of living through that time.
Horshack takes on the role of Cyrano de Bergerac for the school play. But when the other Sweathogs rank on him, he gets upset and runs away. Now, since nobody can find Horshack, Barbarino has to go on stage in his place as Cyrano.
The Sweathogs visit a radio station and get introduced on the air. When Freddie gets his turn to talk, he proves to be a big hit and develops a large fan following, but the other Sweathogs become jealous of his success.
The Welcome Back, Kotter flashback episode. The Sweathogs throw Kotter a surprise party before the start of the new semester. During the party, Kotter and the Sweathogs reflect back on all the good times they had over the first two seasons.
Kotter buys Barbarino's share of the Sweathogs' lottery ticket, but Barbarino says he wants no part of it because they never win. When they do win the $1,000 semifinal prize, Barbarino and Kotter disagree on who should get the money.
Kotter refuses to help Barbarino study for his test that would promote him to the eleventh grade. So the Sweathogs make a deal with Kotter. If he helps Barbarino study, they will help Julie and the babies.
The Kotters are looking for a new apartment and having no luck. Juan has an answer to their problem. His Uncle owns a building in a good neighborhood at the right price. The gang helps the Kotters move in and everything seems to be going great...until Moe Epstein tells them that there are no babies allowed.
Woodman writes a novel set during the Civil War era that very closely parallels the Sweathogs, and the Sweathogs are not happy about it. So they write a novel of their own set in outer space and depicting Woodman as the villain.
The Sweathogs' singing group wins the city-wide talent contest semi-finals. Then Barbarino becomes infatuated with one of their finals competitors. When they start dating, it jeopardizes the Sweathogs' chances of winning.
When Woodman's contract for renewal is up, Kotter decides he wants to apply for vice principal. Then he has a dream that he is the king of Buchanan High School and the very old Sweathogs want to oust him from power.