A/N - Thank you for the love on the last chapter!

This prompt was by jkl on April 29th, very slowly working through them! Sorry if I haven't reached yours yet.

Anna develops a fever and appears to become deathly ill, But it's because her latent fire powers are coming to the surface, and the aftermath.

It had escalated so quickly, a wildfire of the cells, a burning that couldn't be tamed.

It had become telling when Anna was seen slowly making her way around the halls, each step appearing to be made with hesitancy. Staggering, rather than skipping. Elsa knew she had intervene. As much as Anna opposed, Elsa insisted on bringing the doctor up when she grew concerned over Anna's temperature. Her fears calmed upon being told it was nothing more than a fever. The day ended with Elsa reading a story to Anna, sprinkling snow above her bed to keep her cool. She almost went as far as to cook for her, but decided it best that it was left for the Gerda and Kai, to prevent further illness.

"Elsa please, I'm okay you can go to bed" Anna groaned, Elsa had somehow made it onto the third book. Although well intentioned, Anna had read every book in the Castle, some on numerous occasions. The talking - it was giving her a headache. Elsa obliged, but stayed by Anna's side - much to Gerda and Kai's warnings of contagion.

The second day, Anna was bedbound. Stuck between a horrible mix of shivering and feeling overwhelmingly hot, as though her skin just might peel off. The drought inside her throat had taken hostage of her thoughts, and no amount of water could cure it. It accelerated unlike any illness the palace staff had encountered. Enough to warrant Kristoff being collected from the mountains, and for Olaf to be kept close by. Their reunification was heartfelt, Kristoff instantaneously understood Elsa's growing worry. Their conversation was staggered, much of what Anna was saying didn't make sense anymore. Olaf grew quiet, which was unimaginable. It was unnerving, biological challenges were something they couldn't fight. Elsa hated not having control, but she continued as best as she could to keep things cool, despite Anna's protests of being cold.

The third day was so much worse. Anna had become but a vessel for her soul. "The trolls, they might be able to help." Kristoff suggested, looking over at Anna with sadness. There was so little life, the Anna he knew was undetectable, all her joy and personality vanquished by whatever was spreading through her body.

Following Kristoff to the front door, Elsa discussed how crucial it was that he hurry, how she had been briefed that they were running out of options, with no working treatment to reverse some of symptoms. or decrease, it truly appeared as though things could only get worse.

Upon his departure, Elsa found herself staring at their family portrait. She couldn't lose her sister, not to this. Why this fever? They had got through colds and flu before. Then, she allowed herself to cry. It had been the first moment she had alone since Anna's illness began, having not left her bedside Elsa kept her feelings to herself.

Anna's Bedroom

Olaf could only describe it as sunset coming early, he awoke to the sight of a warm orange. Then he caught up, the sound of Anna panicking, she was active as ever, bright (an understatement) and alive. Fire, there was fire.

"Anna?" Olaf gawked as Anna flailed around, she was waving her arms frantically, any faster and Olaf was sure she would take off.

Then the orange burned brighter, and was much too close for his liking. In her flailing, Anna had set Olaf's twigs alight.

"Anna!?" He repeated, screeching. He dived into a nearby vase, the surface of the murky water bubbling as Olaf spoke, "This isn't good" The words were disjointed and not at all audible, even if Anna had been paying him full attention. . It was a good thing the princess had been so unorganised, she hadn't yet placed any flowers inside.

"I'monfireI'monfireI'monfire" Anna incessantly muttered, desperately trying to shake away the fire brewing in her palms. Unknowingly, she was inadvertedly throwing fire around the room, only causing her to panic further.

"Elsa!"" Olaf jumped out of the safety of the water, wailing for the Queen - in this case, so he hoped - the mobile fire extinguisher. "Fire!" He cried, his carrot nose shivering in terror.

Darting down the hallway, Elsa's heart dropped at the sight. Flames were engulfing Anna's childhood bedroom rapidly, and she was at the centre of it all. Thrusting her hands forward, Elsa immediately showered the room with ice. Following Anna's movement, extinguishing the fires she was continuing to create mere seconds after.

"I don't know what's happening" Anna breathed, guilt flushed across her face in crimson red.

"It is curious." Olaf commented, feeling much calmer in the safety of Elsa. As chaos continued to ensue behind him, Olaf retreated to the side of the vase, opting for this moment to think out loud. "If Bruni is the fire spirit where do you fit into this?" He questioned. The Princess continued to try to help her sister in stopping the fires, every time one started she would go after it, attempting to put it out herself, to no avail. "You are a bridge so maybe you're both spirits? Maybe you're the human spirits. maybe you share 1/2 the fifth spirit each.?" He trailed off, deep in wonder oblivious to the apocalypse unearthing just feet away from him. By now, Elsa was trying her best to coach Anna, bidding for her to calm down whilst simultaneously exhausting her powers with every new fire. "Because lets be honest, an ice spirit never made any sense anyway, ice is just frozen water." He shrugged, "What's next a smoke spirit? A fog spirit? Delving into these questions are important in situations like these..." He paused, as though his brain just connected back to Earth's signal. "Situations like these."

Spinning round, Olaf's jaw dropped upon seeing what was Anna's room. Windows had been shattered, paintings were melted and black smoke had decorated the walls, alongside it, ice. The mix of black and light blue was stark, any warmth that had resided in this bedroom had been ruined. Anna was a wreck standing on the bed, scared to even make a movement. Elsa's arms stayed raised, predisposed for any further flames.

"Breathe in, 1...2...3..." Elsa gestured, inhaling deeply. It was difficult not to choke, the air was uninviting. Anna shakily obliged, limply repeating Elsa's actions.

"Elsa, I'm scared." Anna hiccupped, tears streaming down her face. "Where's Kristoff?"

"He's gone to get the trolls" Elsa began, upon seeing Anna struck with worry she hurried the last of her sentence "But he is coming back! He is, he'll be here soon, I'm sure."

The sound of sizzling set both sisters on edge. Anna was at a loss of what to do, it was happening when she wasn't even aware of it. Promptly, Elsa sprinkled more snow to stifle the flames, bringing relief to Anna.

"Why has he gone to get the trolls?" Anna asked, breathing deeply.

"We thought you were gonna die." Olaf recalled. Suddenly the bedpost caught fire - as if there was anything left that hadn't already been burnt - Elsa accompanied the extinguish with a stern look to the snowman.

"But you're okay now, we've got this under control."

"Have we?" Anna wept, the same cry that was found when Anna dug herself into ice cream after an argument with Kristoff. Highly emotional, with no energy for brain power. Anna was still adjusting to what she still believed to be a blip, not her long-term reality.

"All that fire, heat. It must of caused your fever." Elsa mused quietly, "But it was a part of you, you can't remove that. That's why it just got worse, but then you erm.. you let it go" She cringed.

"A part of me?" Anna's head shot up. "Like for forever? Never going away?"

"Maybe" Elsa said wryly.

Halting their conversation abruptly, Kristoff had arrived with Grandpabbie.

"Holy shit." He mouthed, examining the crime scene before him. "What happened?"

"Anna has fire powers." Olaf deadpanned.

"Wha.. how?"

"Is it any use questioning the what's, why's and hows?" Imitating a philosopher, Olaf could only come to the conclusion that nothing made sense anymore. It was best to not ask, as the answers would usually come to them one means or another.

A/N - I am still accepting prompts. Thank you to jkl for this suggestion, my apologies that this isn't the best, it wasn't that angsty. Maybe I might come up with a better story another time.