For their summer vacation, twins Dipper and Mabel Pines are sent to live with their great-unclenote Stan Pines in the valley town of Gravity Falls, Oregon, where he owns the Mystery Shack, "the world's most bizarre museum". Dipper and Mabel's situation worsens (or, rather, betters) when Dipper finds a mysterious book, the cover of which is marked with only the number "3" and a hand with six fingers. Upon opening it, Dipper finds a Great Big Book of Everything explaining the many strange beings, past events, and even federal cover-ups that exist within this town of secrecy — all cut through with an urgent warning: Trust No One! Thus begins Dipper and Mabel's adventures as they interact with the supernatural world that surrounds them.
After the first season finale, the series went on a year-long hiatus. Several Miniseries were released over the break to keep fans satisfied, including:
- Dipper's Guide to the Unexplained, where Dipper attempts to make documentaries explaining supposed mysteries around Gravity Falls.
- Mabel's Guide to Life, in which Mabel gives out handy tips to enjoy everyday life.
- Fixin' it with Soos, a short series of videos that has Soos trying to fix various things around the Mystery Shack.
- TV Shorts, which consist of a few sketches depicting Gravity Falls' TV programming.
- Mabel's Scrapbook, which follows the Pines family on vacation outings.
Season 2 premiered on August 1, 2014, a year after Season 1. The series was rebranded as a Disney XD original series, with episodes premiering on that network first before airing later on Disney Channel. On November 20, 2015, Alex Hirsch announced that Season 2 would be the final season, with the Grand Finale airing February 15, 2016, as a one-hour special.
A DVD/Blu-ray of the complete series was also released on July 24, 2018 from Shout! Factory, making it the first Disney animated series to receive such a release. You can vote for your favorite episode here.
Other media from this series includes:
- Dipper's and Mabel's Guide to Mystery and Nonstop Fun!, an activity book written in an in-universe style by Dipper and Mabel.
- A video game, Gravity Falls: Legend of the Gnome Gemulets, released for the Nintendo 3DS on October 20, 2015.
- Journal #3, a Defictionalization of the iconic book found by Dipper was released on July 26, 2016.
- A Choose Your Own Adventure book, titled Dipper and Mabel and the Curse of the Time Pirates' Treasure! was also released on July 26, 2016. The story is about the Pines Twins time-traveling to find a treasure trove hidden by Time Pirates.
- Don't Color This Book! It's Cursed!, a coloring and activity book with an Excuse Plot of Dipper being trapped in a magic coloring book.
- Gravity Falls: Lost Legends, a graphic novel released on July 24, 2018. It features four stories featuring the Pines family that took place during the second half of the final season, all written by Alex Hirsch and illustrated by a number of talented artists.
"Bewarb" of spoilers.