A Summer that I won't forget

Let's say the Pines Twins never went to gravity falls when they were twelve. They couldn't go last minute because of an family emergency. Simple as that. The towns folk have already moved on and have all agreed to forget what happened.

Dipper and Mabel thought it would be a great idea to spend their summer at Gravity falls. They wanted to visit their great uncles. They wanted a nice summer and they always wanted adventures.

When Stan and Ford defeated Bill they didn't fully kill him. He was still alive and waiting for someone to release him from his stone prison.

Bill wants revenge. But something changes his mind or was this a trick? A demon looking for a second chance or a demon wanting payback?