In the middle of yet another one of their fights, Bart and Lisa stumble into the basement of Professor Frink's house, where he has been expecting them; it seems that he has perfected the science of predicting the future through astrology. He shows them a glimpse of Springfield "Eight years from Tuesday", where Bart and Lisa are getting ready to attend their Senior Prom before graduating together; Lisa is not only graduating at age 16, but has a scholarship to Yale provided by Mr. Burns he started as punishment for cancelling Christmas. One small problem; Bart's girlfriend isn't happy with his plans for their future, but when Bart saves Mr. Burns from a robbery, Burns gives Bart the chance to go to college - by giving him Lisa's scholarship.
While walking through Springfield, Bart and Lisa childishly squabble over who is "gay for Moleman" - fighting, they roll into Professor Frink's basement. He welcomes them, saying that his new astrology machine told him they would come to his house, and he goes on to show them a film of how life will be in their final days of high school, eight years in the future.
In 2013, Bart and Lisa are graduating. Lisa is doing this two years early, and is bound for Yale. She goes to the prom with a muscular, emotional Milhouse, having only agreed to this after he saved her from a house fire that he caused when she was twelve years. Bart is in love with a blond girl, Jenda; after the prom, Bart proposes to Jenda, but she turns him down and ends their relationship, because she doesn't believe he can provide for her.
Meanwhile, Marge has separated from Homer after he blew the family savings on an underwater house. Homer takes Bart to a night on the town in his hover-car, as Donald Fagen’s IGY (International Geophysical Year) plays in the background, but the only girls they find are Mrs. Krabappel and Ms. Hoover. Bart then decides to get a job at the Kwik-E-Mart. While making a delivery to Mr. Burns, he is held at gunpoint by Snake (who now uses a combination phaser/cellphone), but Bart saves Burns when Snake is distracted by a phone call.
As a reward, Burns offers to send Bart to Yale with his scholarship, which was previously promised to Lisa. Believing it will impress Jenda enough to take him back, Bart accepts. When Lisa finds out at their graduation, she becomes furious with Bart. Meanwhile, in the audience, Homer fights Krusty, whom Marge is now dating.
Jenda does indeed take Bart back, now that he has the scholarship. Meanwhile Lisa, dejected, decides to settle for Milhouse. While walking with Jenda, Bart finds Professor Frink's house, and uses the astrology machine to see what the post-2050 future holds for Lisa and Milhouse: they live a nowhere marriage and Milhouse sells all his bone marrow just to pay the electric bill, which still isn't enough. Bart rushes away to save Lisa from life with Milhouse, and gives her the scholarship.
Jenda dumps Bart again, and he decides he wants a girl who loves him for himself. In the present, Frink tells Bart he will find that special girl... one minute before he dies at the age of 83. Meanwhile, Homer has won back Marge's heart by getting beaten up by Krusty.
Superintendent Chalmers is in a Christopher Pike-like persistent vegetative state after taking the drug stim. All he can say is, "Skinner!"
Nelson impregnated Sherri and Terri, who each gave birth to twins. He then deserts them both, similar to the way his own father deserted him.
The United States is in the midst of Gulf War V, "Operation: find our president's head".
Scientists have invented magic.
Moe has a clone and a spider clone (because a spider entered the cloning machine). All three pursue Marge's love.
Mr. Burns, now a 112-year-old shut-in, sponsors a Yale scholarship as punishment for stealing Christmas. He keeps diamonds to have them changed into Earth's most precious mineral of the age: coal. His home is also guarded by a large group of unicorn-clam creatures (uni-clams).
Smithers (who apparently was gay after all) becomes heterosexual, as long as he takes special injections every ten minutes.
Patty now has a fluffy tail because of plastic surgery.
The U.S. Dollar has been replaced by the "Reagan". There is also a 51st state: Saudi Israelia, and apes are trying to get the right to vote.
Snake's weapon of choice is his phaser/cell phone.
Genetically modified foods have led to smart puke, capable of moving on its own.
Singers at prom night have been replaced with iPods. A-ha remains overplayed.
Prof. Frink seems to have hung himself; his skeleton hangs from a rafter in his basement. However, in Lisa's Wedding, Frink is still alive and working to find a cure for Mr. Burns' seventeen stab wounds to the back.
The garbage man uses a spaceship. (similar to the one from E.T.) It has to fly all the way up to move to the next house.
Blinky the three-eyed fish has hundreds of descendants; a three-eyed whale is even shown.
Marriage has become a three-year commitment.
Teens have a new social interaction: "getting some forehead" (head-butting).
Nominated for a 2005 Emmy for Outstanding Animated Program (for Programming Less Than One Hour), with Family Guy's "North by North Quahog", Samurai Jack's "Episode XLIX", South Park's "Best Friends Forever" and SpongeBob SquarePants' "Fear of a Krabby Patty". The winning episode was South Park.