If Stanley had known that his prison bunkmate was as stupidly crazy as he seemed, Stan would have gone on a massacre, rather than the pickpocketing that landed him in the minimum security prison in the first place. Too bad one Danny Fenton had other ideas.

After a wrong turn sends the Fenton family to Gravity Falls, Oregon instead of California for summer vacation, Danny finds himself getting suspicious of his new surroundings, and he's determined to find out what, with the help of the Pines twins. Meanwhile, Dipper begins to get paranoid that there is something off about Danny Fenton, and to top it off, Bill has other plans.

As a new school year begins in Amity Park, Danny Fenton finds himself dodging the new paranormal researcher in town, while befriending the man's great-niece and nephew. But with nightmares and new threats lurking on the horizon, keeping secrets from a nosy scientist will soon be the least of the ghost boy's worries.