Finn had a pleasant awakening as sunlight came through the window onto his face. The sunrises in Ooo were always beautiful, but there was something different about this sunrise. Finn decided it was nothing and got out of bed. "Time to get up, Jake," said Finn groggily. "Huh?" asked a female voice coming from Jake's bed. "Jake? What's wrong with your voice?"
"Who's Jake?"
The figure in Jake's bed turned over. Instead of being Jake, the figure was a cat that Finn had never met before. Finn grabbed a sword from beside his bed. "Who are you, and what have you done with Jake?!" shouted Finn raising his sword. "My name is Cake, and I could ask you a similar question! Where's Fionna?!"
"I don't know who this Fionna is, but you'd better tell me where Jake is, so says Finn the Human!"
"As much as I'd like to introduce you to my claws, we'd better see if Prince Gumball can figure out what's going on."
"Prince Gumball? Don't you mean Princess Bubblegum?"
"Never heard of her. Prince Gumball rules the Candy Kingdom here in the Land of Aaa."
"Princess Bubblegum rules the Candy Kingdom, and we live in the land of Ooo."
"We'd better get to Gumball's quick."

And so, Cake took Finn to Prince Gumball and they explained everything. "Now we need you to figure out what the Math is going on!" shouted Cake at Gumball. The Candy Prince proceeded to scan Finn with a remote-shaped device. "Great Glob! By these readings, you're from a parallel dimension!"
"Whaaaaaaaaaaaaaaaat?!"
"Let me explain. Y'see, our world is only one in-."
"A multiverse of others. Some worlds can be accessed by naturally occurring wormholes, yadda yadda yadda. I know, dude. The Enchiridion told me that after the Lich took over Billy."
"Okay… you get the basic idea, but we still don't know how you got here or which world in the Multiverse is yours."
"I'm from the Land of Ooo. It's similar to this place, but everyone's the opposite they are here. For instance, you're supposed to be a princess, and Cake here is supposed to be a dog named Jake."
"I may be able to pinpoint your home dimension, but it'll take time."
"Why don't I show you around, let you meet some of my friends?"
"Sure, Cake, that sounds pretty sweet!"