Wierdmageddon falls

In this au the Pines family never defeated Bill, Giddeon is Bill's second in command. Stan, Ford, Old Man McGucket, Dipper, Mabel, Soos and Wendy are all in hiding because there's a price on their heads. Dipper and Mabel have just saved Pacifica from being captured by Bill's henchbats and are making their way back to the mystery shack when they find a young girl with huge blue eyes and a birthmark of a closed eye crossed out by a scar on her forehead. They don't know who she is or where she came from, all they know is her name and age but they trust her anyway.