Dipper and Mabel go back to Gravity Falls for the summer, and they are immediately met with chaos, mystery, and more weirdness. Now with the family fully reunited how will they approach all the new madness descending on Gravity Falls? And with their return comes a new mystery surrounding a family member from long ago and their story that had yet to be told. And lurking in the dark is a new threat, desperate to have their revenge. With a plot to to destroy all of Gravity Falls from the inside.