Author's Notes: Hey all! This is my first fanfiction, so comments and criticism is appreciated! The ending and some of the middle has already been planned, but there will be creating some of the story as I go along, so let me know if it has any continuity errors or otherwise! This will be taking place 1 week after the Star vs. the Forces of Evil season two finale, "Starcrushed" and exactly two years after the Gravity Falls premier, "Tourist Trapped". I'll probably be making some sequels and prequels to fit both universes together better. I'll be updating very frequently (probably at least two or three chapters a week).
Star vs. the Forces of Evil is the intellectual property of Disney and Daron Nefcy and Gravity Falls is the intellectual property of Disney and Alex Hirsch. I own no part of either shows.
UPDATE: Due to the events of the Star vs. The Forces of Evil Season 2 Finale, "Starcrushed", I am slightly changing the first three chapters of this story and the direction it will be heading in.
Chapter 1: Do We Have A Deal?
"It's not as difficult as it sounds!" said a strange human-shaped shadow. "Trust me. All we need are those three journals I helped you find."
The 14-year old boy in the red hoodie reached over to his desk and looked at one of his and Star's many pictures together.
"Are you sure about this?" asked Marco. "Is there really a way to get to Mewni in this "Mystery Shack"?
"Of course!" the shadow replied. "Everything will make sense soon."
"What's the catch?" asked Marco.
"The only catch is that Star will be stuck as Toffee's prisoner forever if you don't open the portal. So…do we have a deal?" the voice concluded.
Don't worry, this chapter is meant to be short; the others will be much longer! Working on the next chapter now, so it should be posted today!