The Pines Family resolves to get back to normal by throwing a "Mystery Shack is Back" party but accidentally find themselves in the midst of a zombie assault.
When Dipper's secret journal pages lead him and the gang to the author's hidden bunker, they find themselves coming face to face with a mysterious figure from Gravity Falls' history.
After being belittled by Pacifica too many times, Mabel challenges her to a miniature golf off, which gets out of control when some local residents offer their help.
Soos makes a promise to his grandma that he can find a girlfriend in one week, and buys a dating simulator game to help him learn how to talk to women.
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.