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Lisa tells to Bart that in three days, it's Mom and Dad's anniversary day, Bart remember what she gave them last year and intend to beat her this year. He goes to Professor Frink to collect money for a gift and employees as a cleaner. He begins to clean up his time machine and accidentally start the machine, and they both gone back in the time.
Bart introduces himself as "Homer" and end up in Homer and Marge class. Bart jumps out the window with the joke book and diary, and being chased by all students in school but after he wrapped Snake's skateboard, he manages to escape. Marge and Homer then tells to each other that they feel sorry that he stole the other's stuff and they go away together and play kick the can.
Bart comes to the time machine where Frink is ready to go and he says he barely changed something before they go back. Frink then ask Bart to continue to clean up but he says he does not need it anymore and runs away. It's the anniversary day and Marge and Homer wonders how he got hold of the gift, which was what he stole from their childhood. Lisa is jealous at Bart because he's the best gift but Maggie show then an even better gift, which makes Bart furious. Lisa whispers then to Maggie that because I helped you to beat Bart, you get an extra cookie for two weeks afterwards.