

Twins Dipper and Mabel Pines visit their eccentric great-uncle for a summer in Gravity Falls, Oregon, where he operates the world's most bizarre museum. As soon as the twins arrive in Gravity Falls, they discover something amiss in the remote town.
When Dipper and Mabel hear rumors of a sea monster that lives at the bottom of the local lake, they enlist Soos to take them on a boating expedition to prove it really does exist.