A Prophecy to Fulfill

A tree, a star, and top hat unite.
A sentence from a mysterious prophecy.
A portal in a clearing.
A golden-eyed girl, shrouded in mystery.
What do they all have in common? They have the potential to save or destroy, billions of worlds.
It's been another year, and a new series of adventures begins. It's been a year since Bill Cipher was rescued from the Multiverse by Dipper Pines, and as they search for Ford, all the while trying to solve a mysterious prophecy, they set out on a journey to save their friends, their family, and multiple worlds. With all hopes resting on them, even the smallest choices have the biggest effects... and their mission lies in the past.
Note: This is the third book in a series. The first book is called Fallen Gods, the second one is called Lost in the Multiverse. Enjoy!