In the sleepy town of Oregon, it's going to get a little weirder, it's going to get a little wilder. When two teens arrive out of the portal, Stan's plan is ruined.
As Mabel and Dipper get to know their new guests, they discover their names are Star Butterfly and Marco Diaz. Dipper, being the monster hunter he is, soon bonds with Marco, a monster fighter. As for Mabel and Star, they have already quickly befriended one another.
Now with Stan trying to restart the machine's portal, he tries to bring the teens back home, as well as his mysterious stranger to Gravity Falls. But, everything isn't as it was. Everything is now twined and twisted together from magic spells, rainbows, and laser puppies to monsters, demonic deals, and The Author of The Journals. Fates will be changed, for the better or worse.