While eating dinner at the Simpsons' house, Krusty reveals a side of himself that is nothing like the "happy-go-lucky" clown they all know and love. Ever since his father disowned him for not carrying on the rabbinical family tradition, Krusty has been devastated. Bart and Lisa realize that Krusty needs to make ammends with his father.

Reverend Lovejoy, who appears with Rabbi Krustofski on a weekly radio show, gives Bart and Lisa the rabbi's address. When they visit him, Krustofski tells them that he has no son and slams the door in their faces. Bart and Lisa try to reason with the rabbi and even search the Talmud, the ancient text of rabbicanical wisdom, for a solution. However, nothing can convince Rabbi Krustofski to reunite with his son.

When Bart quotes an inspirational phrase from the entertainer Sammy Davis, Jr., Rabbi Krustofski recognizes his mistake by not acknowledging his offspring. Father and son celebrate their reunion on Krusty's show.