Guest star Bobby Rydell sings "Sitting On Top Of The World," and "Toot Toot Tootsie Goodbye." After the show, Jack is followed home, and a rock is thrown through his window. The rock thrower turns out to be Dennis, who is mad at Jack because Bobby sang instead of Dennis Day. Jack decides to take the law into his own hands, when he punishes Dennis. (thetvdb.com)