One day, Mabel and I were outside when all of a sudden...
"AHHHHHHH!" A scream echoed around us, and then 2 creatures fell down from the sky. One was some sort of dragon, and the other was a pony with wings, and a horn.
"OWWWWW... Remind me never to open a portal in the sky ever again, Sarah!" the pony said, getting up.
"DJ, might wanna look in front of you... I know where we are now... Gravity Falls, Oregon." The dragon said, pointing at us.
"Get away from us, monsters!" I said, looking through the journal but finding nothing on them.
"Relax Dipper, we're friends." The dragon, apparently named Sarah, said.
"H... How do you know-" I had said, before Sarah cut me off.
"We know a lot about this universe, Dipper. Oh! Allow me to introduce ourselves. I am Sarah, and this is my brother DJ, and before you ask, no, we are not twins." Sarah said, before suddenly turning into a human, as did DJ.
"Woah! How'd you do that?!" Mabel asked, walking up to Sarah.
"Mabel! Don't touch them!" I said.
"Dipper, we have not come to hurt you. We bring a message, and assistance," DJ said.
"2 worlds collide," Sarah said.
"Soon they will doom each other." DJ said.
"Cipher's wheel will become larger," Sarah said.
"And four will have the power to save both worlds." DJ said.
"Four? But there is only two of us!" Mabel said.
"2 more will come when the worlds collide, my friend." A voice said.
"BILL!" Mabel said.
"Ahhhh! Rehpic Llib! So glad you made it!" Sarah said. "Dipper, Mabel, this isn't your world's Bill. This, is reverse Bill."
"Who?" I asked.
"A reverse version of your Bill. He is good." DJ said.
"HA! As if!" Mabel said. "You're gonna hurt us, aren't you, 'Sarah'?"
"No no! Dipper, if you would look up the multiverse in the journal?" Sarah asked.
"Okkkkk..." I muttered uneasily. "Woah! This is amazing!" I said a couple minutes later.
"Now do you believe me? We met the author, that's why we are in there." Sarah said.
"Wait... Tell me, are the other two, by chance, these two?" Mabel asked, holding up a picture of two kids.
"Yep. That's them. Gideon and Pacifica Pines." Sarah said, to our amazement.
"But... We aren't related to them..." I said.
"HA! Told ya those kids looked out of this world!" Mabel said.
"Bad pun Mabel, bad pun." A voice said.
"Jess?" Sarah said, turning around.
Then all of a sudden... "AHHHHH! FUUUCKKKKKK!" A voice said, and then a person fell out of the sky.
"Anne-marie? How'd you get in the portal?! I thought I closed it!" Sarah said, helping the new arrival up.
"Holy shit. Are we in Gravity falls?! Are you the human who always has the journal and shit?" The first of them asked.
"Yep. We are, Jessica. And please! Control your cursing! There are children nearby!" Sarah told her.
The other one, Anne-Marie, said, "Jessica, remind me never to go headfirst into a port-" before collapsing.
"Yikes!" I said, running over to him. I thought it was a he. "Is he ok?!" I asked.
"You mean is SHE ok." Sarah said, picking her up. "And no, it's a side effect of going through a multiverse portal for the first time. Jessica has gone through one before." Sarah glared at Jessica.
"Wellllll excuseeee me! I wanted to know where you were going! I didn't know you were going to another universe!" Jessica said.
"Dipper, can we head to the mystery shack? She needs to get inside... In fact, I think we all do." Sarah said.
"Sure." I said.
"Yeah...traveling through portals for the first time is bad." Jessica said nonchalantly and looked over at Sarah.
"Shut up, not my fault." Sarah said. "YOU were the one who decided to follow me."