A dark figure walked towards the tree house that Finn and Jake share, it was around midnight, the moon shone bright down upon the grass kingdom, Finn and Jake were asleep, but BMO was not, he was staring out the window when he noticed the figure and switched to camera mode. The dark figure then carefully set what appeared to be a package at the door step, and then in a split second, the mysterious figure, was gone.

6 hours later

BMO was in the kitchen, cooking up some breakfast for out heroes. Tasty eggs, pancakes, and bacon from meatman. "Finn, Jake! Wake up, breakfast!" shouted BMO in the direction of the ladder that leads to the bedroom. Jake was the first to wake up, the wonderfully intoxicating smell hit his nose as he stretched and grabbed Finn and pulled themselves down to the kitchen "Jake? Did you just stretch us downstairs before I even woke up?" said Finn drowsily "Yep! Haha!" replied Jake with a smirk BMO then placed their breakfasts onto plates and served it, but he wasn't smiling as usual. "BMO, is something wrong?" asked Finn with a concerned look on his face. "Finn, Jake, somebody was here last night."
"Was it Flame Princess?!" "No Finn, it was not, whoever it was left something on the front porch. Here it is." BMO then placed a small envelope on the table; it was addressed to Finn. "It's addressed to you! Probably a LOVE letter from Flame princess!" said Jake, laughing to himself. Finn then took the envelope and began opening it. "Don't be stupid bro, you know she burns everything she touches, including me." "Well, it is a letter, look."

Dear, Finn
This is a message to you from a person, a person you don't know but wishes to help with a little problem you have on your hands. Enclosed is a map to a treasure. This is not a treasure that will bring riches, unless you choose to sell it, which I highly don't recommend, you need this treasure. It is a necklace, a necklace that gives you compete control over any elemental abilities the wearer may possess, there was once two of them, and however one was destroyed in a fierce fight between those who discovered it. I hope that this does not happen between you and Jake.
Sincerely, The Dark Stranger

"Wow, Finn, why does this "Dark Stranger" guy think we would need a magical necklace?" "I don't know Jake, but when we find it, I do know who I will give it to." "I hate to interrupt, but I was able to catch the person leaving it on tape" interrupted BMO. "Then why didn't you wake us up last night when it happened?!" Shouted both Finn and Jake "I'm sorry, would you have rather me woken you up at midnight?" "Play it will you?" Finn says giving BMO a dirty look.

BMO walks up to the wall and turns on his projector, and the video starts playing, we see the mysterious figure slowly creep up and set the envelope on the doorstep, then, it disappears as quickly as it came.

"BMO, can you play that again in slow motion please?" asked Finn. Then BMO started it over from the beginning and played it in slow motion. "Pause it right there and zoom in" As BMO zoomed in they were able to make out a barbwire tattoo on its left wrist. "Do we know anybody with a barbwire tattoo?" Finn asked Jake "I think so, meatman has one" BMO then pressed play and in slow motion you could see how the figure was able to disappear so quickly, in slow motion you can see the figure fly away into the night, faster than the blink of an eye. "Can meatman fly Jake?" Asked Finn sarcastically "I don't think so" replied Jake.

"So, what do we do now?" asked Jake as he finished his breakfast. "We're going to find that necklace!"