A/N: Welcome to the final chapter of Unthinkable Agony. Yes, it does get a bit lemony, but not that bad. And I hope that you will read and review. I do own any of the characters, just the plot for this story. If you would like a sequel, please let me know, otherwise this will be my final story for Finn and Flame Princess. –Maiden of the Heavens (MOTH)

Fuse

When Finn awoke it felt like a mountain had fallen on top of him and the room spun in circles. He closed his eyes for a moment, and took in deep and slow breaths. His arm was aching painfully, but if whatever Princess Bubblegum had injected him with would let him be with Flame Princess, and then he could deal with the throbbing in his arm where it was bandaged. He carefully made his way off of the bed and let his feet hit the floor; he was a little unsteady at first but was able to make his way toward the basin and pitcher. The Hero of Ooo cupped the water into his hands, but before he could splash onto his face, the water began to sizzle and boil in his hands, until it became steam, that was so hot that it stung his eyes.

Finn cried out in alarm and stumbled backwards, the pitcher that was rocking at the edge of the table, fell off and shattered. He was staring at fingertips in awe, his jaw opened in a large O of shock. His fingertips and somehow sprouted orange and yellow flames. He wasn't sure if he should scream or be excited about the fact that he could conjure fire. He righted his way to his knees and crawled toward the full-length mirror that was against the wall. He touched a hand to it; his fingertips were now only smoking. His ocean blue eyes were speckled with the deep orange color of glowing embers. Finn removed his hat and stared at his hair, the white-blonde of it was now streaked with orange highlights, the tips blood red, and at the very end wisps, a bright yellow. This was him, this really was him. Finn shook his head like a dog shaking off water, and pinched himself. It was not dream, this was real. He wasn't a human anymore, well at least not fully.

He sat back with his feet curled underneath him, and his hands resting on his jeans. He clutched his bear-eared hat in his hands. He looked up as the door was opening and righted himself. The hat fell to the floor with a soft thud. Flame Princess stood in the doorway a big bowl of charcoal in her hands. She carefully set the bowl down on to the table and stepped around the shattered pieces of the pitcher to where Finn was standing. She placed her hand on Finn's navy-blue shirt and watched as the fabric began to peel and burn away from her touch. The shirt was soon ashes, ashes that were now smeared on Finn's shoulders, arms, and fingertips as he tried to brush it off. Flame Princess was staring at him; her hand was still on his now bare chest but he wasn't burning. His skin wasn't turning red from her touch or worse, he wasn't screaming, his skin was not blistering. She could touch him without hurting him. Her eyes lingered on his bare chest for a moment, scorched into his skin as dark as tattoo ink was a flaming spiral over his heart. It almost looked like a phoenix rising out of the ashes.

Finn gently cupped Flame Princess's chin his hand and titled her head up, so he could see her. Lava was pooling at the edge of her eyes and slipping down her cheeks. But he wasn't hurt by flames, and that made his heart beat his chest like a drum. Before he could stop himself, or even think properly, he had both his hands on either side of her cheeks and he was kissing her. He continued to kiss her, until their tongues met and they tasting each other. Flame princess giggled as he kissed her face and her neck, only to realize in mere moments his jeans were gone, and his shoes were starting to melt to the floor. His underwear was already starting to get burn holes in them. Flame Princess slipped her dress off of her shoulders as it pooled onto the floor, she found herself climbing on top of Finn as he now lying on the bed. She intertwined their fingers, a blush creeping up into her cheeks, her flame burning brighter.

"Finn…do you want too…I mean we don't have too…" she stumbled over her words, and found herself even more embarrassed.

Finn kissed her on the mouth and smiled. "I want too."

A couple of hours later, the sun was beginning to set. It bathed the halls of Candy Kingdom in its soft orange glow. Princess Bonnibell found herself knocking on the door of the guest chambers that the Hero of Ooo and Flame Princess were sharing. Not hearing anything, Princess Bubblegum began to panic; she slowly opened and peeked her head in. Her cheeks automatically turned as red as cherries. Finn and Flame Princess were lying on the bed fast asleep, fast asleep and tangled together…naked. Completely butt-naked.

Bonnibell quickly shut the door and braced herself against the wall. Only to find Marceline floating above her and wrapping her ash-grey arms around her. The Vampire Queen resting her chin on Bonnibell's shoulder, a fanged smirked stretching across her face. Her eyes gleaming with mischief.

"He dipped his wick into her flame didn't he?" she questioned.

Flame Princess nodded. "I should have had the talk with him…"

"I think it's a little late for that, Bonnie." Marceline grinned.

Bonnibell sighed, "I know that…"

Marceline steered away from the door. "I say we go fill up the gigantic bubble bath of yours with suds and some fun of our own." She playfully squeezed the Princess butt and laughed, before floating down the hallway with Bonnibell chasing after.

Bonnibell stopped short and looked over her shoulder. "They'll be okay, right?"

Marceline bit her lip one fang sticking out as she now floated upside down with her legs crossed. "Yeah, I think so. Finn isn't that stupid, they'll be alright."

Bonnibell smiled softly, "Yeah, I guess so." She gently kissed Marceline on the cheek.

Finn awoke with the sun in his eyes, surprisingly it didn't hurt that bad. He looked down at Flame Princess and wiped a couple of strands of her hair away from her face. He kissed her gently on the lips and sat up to go get the bowl of charcoal that was on the table. Flame Princess's hand curled around Finn's.

"I love you, honey." She smiled sleepily.

Finn kissed her again. "I love you too."