Season synopsis
Contains spoilers for this season and earlier seasons.
Dipper and Mabel Pines arrive in Gravity Falls to spend the summer at their great-uncle Stan’s Mystery Shack, where Stan sells dubious attractions to tourists. Dipper’s discovery of Journal 3 changes the twins’ view of the town: its monsters and oddities are real, and the notebook offers clues for finding them. At the town fair, Mabel wins the pig Waddles while Dipper steals a time traveler’s machine to undo a failed attempt to impress Wendy. Their growing familiarity with the town’s mysteries draws them into conflict with Lil’ Gideon Gleeful, a child psychic whose public charm hides his hunger for Stan’s business and his own journal.
Gideon turns to the dream demon Bill Cipher to break into Stan’s mind and steal the code to his safe. Dipper, Mabel and Soos follow Bill into the mindscape; Dipper discovers that Stan’s gruff treatment conceals real affection, while Mabel prevents Bill from carrying off the code. That victory does not stop Gideon: he blasts open the safe, takes the Shack and forces the Pines family out. When Stan prepares to send the twins home, they choose to fight back. Gideon pursues them in a giant robot, but Dipper turns its own strength against it. The exposed fraud is arrested and Stan regains the Shack. Dipper shows Stan his journal, which he dismisses as a novelty; that night, the episode reveals that Stan has all three journals and is building a portal in a hidden laboratory.