"The Bubble Boy" is the 47th episode of the American sitcom Seinfeld, as well as the nickname of Donald Sanger, one of the characters in the episode. It was the 7th episode of the 4th season. The episode was written by Larry David and Larry Charles, and it was directed by Tom Cherones. It aired on October 7, 1992. Donald the Bubble Boy is played by Jon Hayman.
Jerry, George, George's girlfriend Susan, and Elaine plan to travel to Susan's family's lakeside cabin. Before then, Jerry and Elaine meet a kindly trucker who describes the sad life of his son Donald, who lives in a plastic "bubble" (a germ-free quarantine). As Donald is a fan of Jerry's, Jerry is forced by Elaine to visit Donald on the way to the cabin to cheer him up. However, Jerry gets lost and George and Susan arrive before him. While waiting for Jerry to arrive, they play Trivial Pursuit with the "bubble boy," who is in fact actually an adult, and not a mere boy.
The episode relies heavily on dark comedy in the portrayal of the bubble boy. American journalists had in the past covered "bubble boys" who lived in quarantine due to an immune deficiency. The coverage often played for sympathy, ignoring anything about the subject other than his medical condition. The bubble boy in this episode, however, is a rude, selfish lech who is impossible to sympathize with.
The Trivial Pursuit game ends prematurely when George disputes the answer to the question "Who invaded Spain in the 8th century?" The boy answers with "the Moors", but the question card says "the Moops" due to a misprint, and George refuses to give Donald credit. Donald attacks George and the "bubble" is punctured and depressurized in the struggle. Although everyone blames George for popping the bubble, technically, Susan causes it as she tries to defend George from Donald's attack.
Donald does not fully appear on-screen, except for a pair of gloves that he uses to reach through the barrier. Later, when he is exiting the house on a stretcher, he is partially covered by paramedics.
Meanwhile, Kramer and Jerry's girlfriend Naomi (played by Jessica Lundy) attempt to rendezvous with Jerry, Elaine, George, and Susan at Susan's family's country home. Kramer carelessly leaves his lit cigar near some newspapers, which causes a fire that destroys Susan's family's cabin. The other four travelers arrive as the firefighters arrive.