When Dipper tries to impress Wendy by acting older than he really is, he's invited to join a group of teenagers that leads to an old abandoned convenience store that may be haunted. Mabel tags along for the ride but gets sidetracked when she sees a discontinued line of flavored candies that sends her on an unexpected adventure.

Stan throws a big party to promote the Mystery Shack, while Dipper uses a strange photocopier to make clones of himself, so that he can impress Wendy.