Contains spoilers for this episode and earlier episodes.
At Stan's fair, Dipper tries to win a stuffed prize for Wendy, but his baseball ricochets into her eye. Robbie brings ice and uses the opening to ask her out. Mabel has a much happier visit, winning a pig she names Waddles and immediately adores. The twins encounter Blendin Blandin, a time traveler sent to fix disturbances in the past, and borrow his time machine without permission. Dipper hopes to repeat the fair until he can avoid hurting Wendy and prevent her date with Robbie. Mabel cheerfully joins his attempts, returning to win Waddles each time they reset the afternoon.
Dipper eventually finds a successful plan, but it requires Mabel's help at the exact moment she normally wins her pig. Pacifica claims Waddles instead, leaving Mabel devastated. The twins fight over the time machine and tumble through different eras, creating more of the disturbances Blendin was supposed to repair. Back at the fair, Dipper refuses another reset, certain that Mabel will get over losing the pig. After seeing how deeply she misses Waddles, he gives up his preferred outcome and restores the original day. Wendy agrees to date Robbie, while Mabel gets her companion back. Time officers arrest Blendin for the unauthorized changes, leaving him to clean up the twins' scattered objects and interference.