A/N: Sorry this is two days late, it's my first time doing Febwhump and I hope you enjoy!
Prompt 1: Mind Control
It was leaching into his brain, eating him from the inside out. A few more hours, he told himself, just wait and Gaius will be able to subdue it again. The snake refused to listen to him and continued to fight him; trying to convince him to kill his best friend.
He was fighting it, he would always fight it, but there was no way he could hold it off until they got back to Camelot.
It took him a few moments to realized Arthur had stopped and was now looking at him with concern.
"All right there, Merlin? You're looking like more of an idiot than usual."
With the sluggishness in his brain, it took him a while to repond. "I'm fine Arthur. Why? Are you worried about me?" he said with a grin.
"Don't be stupid," and with that, he turned back onto the path. Merlin watched him for a few moments.
Kill kill you must kill the king you must kill kill.
He shook himself off quickly and kicked his horse into a canter. It was getting harder and harder to push out it's thoughts, and he knew he only had two paths in front of him. He could either hope and pray that the two of them got back to Camelot fast enough, or he could warn Arthur.
Trusting his horse to stay on the road, he debated his two options. If nothing else, it helped distract him from the invading thoughts of murder.
On one hand, if he told Arthur, then he would face the inevitable questions on how, why, and who put a mind-controling snake in his neck. Revealing this secret might just lead to unraveling the tapestry of lies he built over the years, and that was something he couldn't deal with right now. Heck, Arthur might not even believe him until it completely took over which would just ruin the point of telling him in the first place.
On the other hand, he was risking Arthur's life.
The king you must kill kill him kill now the king.
Merlin sighed, this was pretty stupid, even for him. He knew what had to happen to moment his potions smashed onto the ground a few hours back. He pulled his horse to a stop and called out.
"Arthur?"
Ahead of him, Llamrei dug her hooves into the ground, coming to a halt at the sound of Merlin's voice. Arthur turned around, looking slightly irritated that Merlin had more control over his horse than he did.
"Yes?"
"Arthur," Merlin chewed his lip and gave himself another second to rethink his desicion. He sighed and prepared himself for what he was about to say. "Arthur, we need to stop."
The king furrowed his brow, looking at his servant strangely. "Why, your little bottom sore?" he tried to joke, but it fell flat. It seemed that even the emotionally stunted man could tell this was serious.
"No I-we need to stop. Arthur, please."
The concern in Arthur's eyes grew as he noticed the paleness of Merlin's skin and the white-knuckled grip he had on the reins of his horse.
"There's a clearing a few paces ahead, can you wait awhile?" he asked.
Merlin mumbled out an agreement and pushed his horse into a trot. No words were spoken until they reached said clearing. Arthur swung himself off the horse and tied the reins to a branch. He then scruntinized his friend as he did the same thing.
"So, Merlin, care to share what's got you in such a twist?"
Merlin wrung out his hands and did what he usually did when nervous: he babbled.
"I'm sorry I didn't tell you before, but I didn't know how and I thought I had it handled but apparently I didn't because the potion smashed and it's almost been a whole day. I can't hold it off for long, my head already hurts a lot and I can feel it and it's going to make me- I mean I'm going to- I mean-"
"Woah, woah, slow down Merlin." Arthur spoke as if soothing a spooked horse, "What's going on? What didn't you tell me?"
Merlin took a deep breath and let it all out in a rush. "Ihaveasnakeinmyneckthat'sgoingtomakemekillyouassoonasthesunsets."
Arthur's concern was quickly reaching panic levels, but he spoke quite calmly. "Merlin, say that again, but slowly."
"I have a snake in my neck that's going to make me kill you as soon as the sun sets."
They both stared at each other for a long moment.
"You have...a snake in your neck? And it's going to make you kill me?"
"Yes, Arthur, I can't explain right now, but please you have to believe me. I only have a few minutes, and I need you to tie me up." Merlin insisted desperately.
Disbelievely Arthur nodded, "Right."
"Arthur, please! I-" Whatever he was going to say was quickly cut off with a cry of pain. Merlin clutched his head and gasped for breath as the fomorrah initiated a stronger attack on his mind.
Kill kill kill him kill him now you must kill you want to kill kill the king kill him now.
"Arthur," Merlin groaned, "Arthur, hurry, please."
Confusion still filled him, but he went over and got the extra rope out of the saddlebags and brought it over to where Merlin had sunk to his knees. Light keening noises tore out of him as he battled the force in his head.
Arthur shook his shoulder softly. "Merlin, you have to let go of your head if you want me to tie you up, alright?"
He pried pale fingers off of inky hair. By the gods, Merlin was shaking. Whatever was happening was clearly terrrifying him, he thought bewilderedly.
Pulling the younger man over to the closest tree, he wound the ropes over arms and around the trunk. After tying a secure knot, Arthur sat back on his haunches and watched Merlin tremble.
Kill him you want to kill him you want to kill him kill the the king kill him, stab him, strangle him, watch him bleed, watch him Die.
"I-I'm s-sor-sorry," he chocked out, waves of pain assaulting him for his trouble.
Arthur nodded mutely. He put a hand on his friend's shoulder and squeezed lightly. "Don't worry, we'll be fine."
Merlin's trembles turned to shudders, which turned to faint tremors. Both men stayed silent and still as dusk came and the light started to fade.
Then the sun dropped past the horizon, and the demon awoke.
