A/N: I have rebooted my profile and come back into Fanfiction with Adventure Time, if you want the specific details then look at my profile summary it is there. Anyway this was an idea that I detailed in my Future Possible Stories, so people who want to know more have a look. Anyway this is going to be a large project and the only story I will work on for a while. It's going to have 3 story arcs each being approximately 20 chapters long making this story a predetermined 60+ chapters long. This story if Finnceline and also I suck at romance, this is my first attempt so please bear with me and hopefully I will get better as the story progresses. I do not own Adventure Time though I do own any OC's made for this story, also there are some influences from Ooobservers Citadel of Truth and I recommend any to go read that story as it is an epic AT fanfiction.

Finn was running for his life, why might you ask, well it all goes back to this morning. You see this morning was Finns' birthday, his 18th birthday to be exact. This was a big deal because he and Marceline have been together now for the past year, after Finns breakup with Flame Princess the year before, with no problems at all. Today though he was going to propose to her and finally settle down, stop adventures for a bit and have a family.

Now he wasn't running from Jake, actually he was cool with the relationship and supported Finns decision. It wasn't Hudson, as he seemed happy that Marceline was finally with someone stating that he has been waiting 500 years for grandchildren. So again back to the original question, why is Finn running for his life? Well it turns out Flame Princess wasn't completely fixed with her elemental matrix and was now trying to burn Finn alive for not seeing her in ages.

"You said we were done!" Finn shouted as he dodged a fireball that would've killed him.

"I thought you would come back to me, not go out with that, with that, that unholy thing!" Flame Princess shouted in her giant fire form.

"WHAT DID YOU CALL HER?" Finn shouted as he turned around to face FP as she stopped, completely surprised.

"Finn that what she is, she's a vampire Marceline would never be right for you and your hero heart," FP tried to explain as she reverted back to her normal form.

"No you are mistaken here, Marceline isn't unholy she's just a radical dame who likes to play games," Finn said using his old expression of describing Marceline, "She loves adventuring and is able to kick ass as well, in my eyes she is perfect."

"She's corrupted you Finn, and I must purify you," FP said as she made a blue fire sword and charged Finn.

"You've gone insane FP," Finn said as he summoned his grass blade, he had long ago cleared the curse on it with help from Magic Man who owed him a favour for saving him.

Just before both elemental swords could clash though a red axe with guitar strings going along it was placed in the middle stopping both swords. Both combatants turned to the newcomer only to see Marceline standing there, scowling at FP.

"Jeez girl, I also heard you say that you guys were over forever so what do you care about who Finn goes out with anymore?" Marcy asked as she still looked at FP.

"Even so you're just not right for a righteous person like Finn," FP accused whilst pointing at Marcy.

"And so your solution is to kill him and rid Ooo of its greatest hero?" Asked Marcy still sounding annoyed and one could detect slight hints of sarcasm.

FP just looked shocked, looked between the two, hung her head in defeat and flew off back towards the Fire Kingdom in sadness. Finn just turned to Marceline as she turned to him and kissed him, not a passionate one but not a quick one either long enough to get feelings across.

"So what brings you here hero?" Marcy asked with a smirk as she stood there one hand holding the axe bass and the other on her hip as she actually stood for once.

"Well I wanted to ask you a question Marcy," Finn said as his palms became sweaty signifying he was nervous, as he started to get on one knee Marcy just raised a hand to stop him and spoke up.

"Yes," she said and he could see the happiness in her eyes, though he was confused.

"How did you know what I was asking?" Finn asked. His answer came when Marceline showed him her other hand and he saw the black ruby ring that he bought Marceline and his eyes widened in shock.

"You dropped the box as you charged towards Flame Princess and I picked it up, figured out what it was for and made my decision," Marcy said with a bright smile, "you suck at hiding things weenie."

Finn just smiled as he held up his right hand and showed the silver ring that had a sapphire in it which was the partner ring to the obsidian ring with the ruby in it that Marcy was wearing.

As they were walking back to Finns' tree house, Jake had moved out permanently when Finn turned 17 giving him the house to himself, they were stopped by a voice behind them. "Well isn't this touching, a newly engaged couple walking together, well one floating and the other walking but you know what I mean," said a child's voice behind them.

Instantly Marcy and Finn turned on the spot to look behind them not liking the idea of being stalked after just becoming engaged. What they saw was a kid that looked to be no older than 10 looking up at them. He wore a silver hooded jacket that was undone with the hood down and a teal blue shirt underneath. On his legs he wore white combat pants and a pair of steel capped combat boots. He had light blue hair and his eyes were ice blue, he had skin with a bluish tint to it that was very pale.

"Um kid, why were you following us?" Marcy asked, unsure how to react to the kid in front of them.

"Hmm, oh sorry zoned out there are, I am Le-Azi," the kid now identified as Le-Azi said, "as to why I was following it's just that there is a strong force of life energy coming from underneath that house there, might just be my imagination but I'll leave you two alone for now and go investigate later see ya!" Le-Azi started seriously but at the end became joyful and ran off towards the Ice Kingdom.

Finn and Marcy chuckled as the kid ran away and then turned around and continued their walk to the house, however Finn couldn't help but be curious about what Le-Azi had said and decided to check out the house when they got there.

When they walked in instead of going to the living room Finn started walking to the armoury confusing Marcy as she looked at him with a weird look, one eyebrow raised, "Finn where are you going, are you actually considering what that kid said."

"It doesn't hurt to look now does it?" Finn said from the other room. Marceline just sighed dramatically and floated after him. Inside the armoury there were allsorts of weapons and artifacts that Finn and Jake had collected over their numerous years of adventuring. Finn walked up to a locked trapdoor and stood their looking at it whilst Marceline floated over and looked over Finns' shoulder.

"What's that?" Marcy asked. Finn just shrugged.

"It's always been here just never opened it as me and Jake assumed it was locked for a reason and left it, now I'm curious," Said Finn as he went and got a sledgehammer, "Stand back Marcy," Finn said as he swung the hammer and Marcy got out of the way. The hammer destroying the lock and the door flung open to reveal a staircase down into what looked like a chamber.

A smile made its way onto Finns' face as he saw it and Marcy saw that look and sighed, "You want to look down there don't you?"

"Heck yeah but first lets call Jake and PB they could help us down there and I know Jake will want to see this," Finn said as he made his way to the phone, excited for the prospect of a new adventure in 2 years. Oh how he didn't know that going down there would be the start of his most life threatening adventure yet since his adventure to take on the Lich.