Bill cast a spell on the town of Gravity falls. Suddenly everyone is a monster. They want to turn back, but they don't know how. And, they can't leave the town because Bills spell only affected Gravity Falls. What will happen?

When Dipper and Mabel's parents suddenly go missing and later are found dead, they are sent to their great uncles house. Ther they are forced to work/ prefrom while Stanley drinks whiskey. Then accidentally Mabel summons a demon who can posses her and comes or goes when he pleases. While Mabel is trying to fight for her life Dipper is tracing the clues to his parents murder claimed a suicide. Will he find the killer beffore the killer finds him? Will Bill Cipher triumph over Mabel's body? More importantly who will be the first to die , fall in love , or betray the twins? Could it be someone they are close to?