When Bart sees a commercial for the ultimate cruise, he begs his parents for a family vacation. Low on cash, the only way they can go is if each family member sells one valuable. Once they're away, Bart is determined to make the vacation last forever. So he comes up with a plan to make sure they never have to return home in the all-new "A Totally Fun Thing Bart Will Never Do Again" episode of THE SIMPSONS airing Sunday, April 29 (8:00-8:30 PM ET/PT) on FOX. (SI-2312) (TV-PG L, V)

Voice Cast: Dan Castellaneta as Homer Simpson; Julie Kavner as Marge Simpson; Nancy Cartwright as Bart Simpson and Nelson; Yeardley Smith as Lisa Simpson; Harry Shearer as Skinner; Pamela Hayden as Milhouse and Jimbo; Tress MacNeille as Dolph

Guest Voice Cast: Treat Williams as himself; Steve Coogan as Rowan Priddis