Bill decides he liked it in Dipper's body,after a year they come back to Gravity Falls for good,but Bill had other plans & ends up killing Soos,Stan and Mabel.But he left Opal. Her only hope is to cope with the insane life of being able to see a ghost & living with a demon. Allie sees that she needs to open the Mystery Shack.But it looks like she's going to need some serious help.

Well, here you have it folks, Dipper challenges Stan and Mabel and chooses to go to the Taco Bell near the forest...But what he didn't know was that there were more secrets surrounding it than he could comprehend...Or just a big snake who hates Mabel's song choice.