The ashes of a pine tree

It's been three years since Dipper and Mable came to Gravity falls for the first time, and now, they are back for another summer in this strange city. But there's only one tiny problem, Bill, is still alive. And he wants revenge, and he knows how to get it. Dipper ends up getting kidnapped by Bill, will Mable be able to save her brother, or will Dipper's rescue come too late.