The Pines family is starting to get everything back to normal after the Lil' Gideon incident. They throw a "Mystery Shack Is Back" party, but some unwelcome guests intend to crash it.
Dipper's secret journal pages lead him and the gang to the author's hidden bunker where they find themselves face-to-face with a mysterious figure from Gravity Falls' lore.
After being belittled by Pacifica one too many times, Mabel challenges her to a miniature golf-off which gets a tad out of control when some local residents offer their help.
Mabel decides to put on a sock puppet rock opera to impress a local puppeteer, but her show goes awry when Dipper's drive to uncover more of the journal's secrets leads to a supernatural disaster.
Soos needs a date for his cousin Reggie's engagement party and looks to a dating simulator game to help him talk to girls.
In three separate mysterious tales, Stan is cursed by a Witch, Waddles accidentally eats a bowl of brain-enhancing jelly and builds a machine that allows him to speak for the first time, and Mabel faces her fear of Claymotion.
The kids, along with Old Man McGucket's help, discover there is a secret society in Gravity Falls.
Blendin returns to face off with Dipper and Mabel in a futuristic battle that could trap them forever in time jail.
Mabel takes matchmaking too far when she steals a love potion from a real Love God.
Pacifica invites Dipper over to her mansion in order to get rid of a ghost, otherwise the Northwest reputation would be ruined.
After agents Powers and Trigger take Stan into custody, Dipper and Mabel begin to wonder how much they actually know about their Grunkle Stan.
Cornered underneath the Mystery Shack, Stan must finally reveal the secrets of his past and his mysterious portal to Dipper and Mabel.
Dipper finds an unlikely friend to join him with his newest obsession - a board game called "Dungeons, Dungeons, and More Dungeons".
When Grunkle Stan decides to run for mayor, Dipper and Mabel have their work cut out for them trying to turn their gaffe-prone uncle into the perfect candidate.
A new threat leads Mabel to venture into the enchanted realm of the unicorns. Meanwhile, Dipper learns an unexpected twist about the enigmatic Bill Cipher.
Grunkle Stan takes the kids with him on a road-trip to sabotage all the other tourist traps in Oregon.
Mabel decides to plan for her and Dipper's 13th birthday party. Meanwhile, Dipper ventures below the town to find its most shocking secret.
Trapped in the apocalypse and menaced by villains new and old, Dipper finds himself in a race against time.
Dipper must convince Mabel to leave her perfect fantasy world and return to the real world to fight Bill.
It's up to the twins and the remaining townsfolk and other residents of Gravity Falls to bring an end to Bill and his minions once and for all to save the world.