"One of Our Sweathogs is Missing" finds Juan Epstein, the toughest kid in school, humiliated after losing a fight with honor student Todd Ludlow (Dennis Bowen's second of five appearances), who objected to his girlfriend being insulted. Too ashamed to show his face in class again, he decides to drop out so he can run away and join the circus! While the other Sweathogs are out looking for him, Juan shows up on the Kotter doorstep to say goodbye, sharing a classic exchange with Gabe and his expressionless face. Vinnie does his 'What-Where' routine when Mr. Woodman's red phone turns up in Kotter's classroom, then it's Gabe's turn to repeat the 'What-Where' with the vice principal! More movie lore galore as Gabe Kaplan and Robert Hegyes exchange James Cagney impressions, and we learn that Juan's father is named Murray, brothers named Pedro, Irving, and Sanchez (Juan is the sixth out of nine children).