Welcome to Gravity Falls Oregon!

That's what an old sign said, before it was broken apart by a weird apocalypse, Weirdmageddan... You're running from three monsters when one bites your ankle and you fall to the ground instantly, one other monster stands over you, it has the intention to possess you, Dipper and Mabel watching in the distance, afraid for you, not knowing what to do

Dipper: Oh no Mabel: We have to do something!