21x22 The Bob Next Door
First Aired: May. 16, 2010 on FOX
Summary: Bart becomes convinced that his new neighbor, Walt, is his arch enemy, Sideshow Bob (guest voice Kelsey Grammer), and Marge tries to convince him otherwise by taking him to visit the state penitentiary. When Bart arrives, however, a disturbing truth is revealed.
Guest Stars[no credits found]