"Oh ho ho Gravity Falls It's good to be back; now who do I have to thank for my swift return?"
He asks turning around to greet the person who summoned him.
"Well this is a surprise, Shooting Star. Why in the world would you summon me back into this world?"
"Its not like I wanted to I didn't have a choice, I.....I need to make a deal."
"A deal you say well now I'm intrigued, alright kid what do you want?"
"I..I want you to..... save him."
.......
"Mabel! What were you thinking summoning Bill back into this world! Did you not think of the consequences!"
"Sweetie I have to agree with him. Not only is Bill back but he has your brother under his spell."
"Your wrong! Dipper isn't under a spell!"
"How could you possibly know that!?"
"Because he's my twin brother! I would know if something was off about him."
"If that's the case why would Dipper willingly go with the enemy!?"
"Be-because."
"Because isn't answer, please tell us what going on."
"Bill's changed, he isn't the enemy he's a friend and Dipper isn't under a spell he's."
"he's what?"
"He's in love."
...........
You're probably wondering what's going on right now well it's a long story. We're going to have to go back to the beginning to understand and this story begins with Mabel Pines.