Please forgive any mistakes. I may continue with this fic because I love Cherik. I am open to constructive criticism! Hope you enjoy!
The sun had faded away and the blackness of a moonless night surrounded the plane. Charles and Erik were only halfway through the game of chess when Charles became distant, his electric blue eyes began to water as he looked to nowhere in particular. Erik took his turn and waited patiently for Charles to make his next move, wondering what far-off state of mind that his old friend was in. After a long while of Charles remaining that way Erik could not take wondering any longer.
"Charles?" He asked lightly. Lightly, yet still Charles startled as if Erik had shouted. He swiped the tears that fell to his cheeks away quickly and cleared his throat.
"Oh- I- I do apologize, Erik.. I'm afraid that we must delay continuing our game for a while.."
"Are you okay, Charles?"
"Hm? Oh yes, I am perfectly alright. I am just extremely exhausted.. I need to rest, if you do not mind."
"Al-alright, Charles." Erik replied, but Charles was already gathering a blanket from the compartment. He collapsed into the chair across the isle from Erik, pulling the blanket up around his shoulders as he reclined back halfway. His eyes immediately closed and it wasn't long after that his breathing slowed and he was fully asleep.
Just as Erik began to allow himself to fall asleep as well his eyes snapped open, startled out of his nearly-dreaming state by a small whimper. He looked immediately to Charles, who's brow was deeply furrowed as he slept. Charles made no further sound and so Erik began to close his eyes again. He startled awake once more at another whimper, a more desperate one this time. Charles' hands were clutching into shaking fists and his breathing became ragged. Erik looked to Logan, but he was fast asleep, and then to Hank, but he seemed like he didn't hear Charles distress in the cockpit.
"Ugh.." Charles moaned, bringing Erik's attention back to him. Charles' breathing became harsher and he tossed in his sleep, fists clutching desperately at the blanket.
"Charles?" Erik inquired quietly, Charles only became more distressed, his whimpering turning to little yelps of agony. "Charles?" Erik said a little louder, yet Charles slept on, trapped in his nightmare still.
Erik could not let Charles' nightmare continue on as his yelps and whimpers turned to small sobs. He leaned across the isle and shook his old friend's shoulder, calling his name a little louder. Charles startled awake violently, sitting up very fast and breathing much to harshly. His electric blue eyes darted around franticly and were full of tears as he attempted to stand. Charles was still perhaps not fully conscious yet, or perhaps he was to dizzy, because his legs collapsed under him. At least that's what Erik thought as he jumped up and caught Charles before he hit the ground. Erik looked to Charles questioningly but Charles eyes were full of fear.
"H-Hank!" Charles shouted, his voice panicked. Erik realized that Charles was dead weight at the moment, offering no support to keep himself up, it was as if his legs were- his legs were useless as he clutched onto Erik. Hank quickly jumped out of his seat, switching on autopilot in the same movement. Erik didn't know what to do as he realized that Charles' legs were becoming paralyzed.
"Charles?" Hank asked as he rushed out of the cockpit.
"Th-the serum-gah!" Charles gasped, his voice full of agony and eyes screwing shut.
"Lay him down." Hank advised Erik as he rushed past them to the back of the plane, hurriedly getting into the compartments there. Erik quickly lowered Charles down to the floor and sat down with him, putting Charles' head gently on his lap as he clutched onto his old friends' hand. Logan remained ,shocked and fully awake, in his seat. Perhaps knowing he would only get in the way if he tried to help. Charles seemed to break then. He began to scream. His free hand flew to his temple, where nails dug into his skull so hard that his skin broke and blood trickled into his chestnut hair and down his forehead. His legs didn't move as he began to shake and thrash, clutching hard onto Erik's hand. He cried out, his voice full of agony. Tears streamed out of his eyes as he shrieked in agony.
"Make- aah!- make them stop-!" He cried. Erik was at a loss on how to help as Hank came barreling down the isle with something in his hands.
"What is going on?!" Logan asked fearfully as Hank began to tie a tourniquet around Charles' upper arm.
"He missed a treatment-" Hank answered as he fought to pull Charles' trembling arm straight. "As his legs go, his powers come back-"
"Make them stop, make them stop-" Charles groaned, his voice thick with agony and tears. "So-so much..pain-ughahh!-please!" Hank found a worthy vain in the crook of Charles' elbow and stabbed a syringe full of amber liquid into it. Without hesitation Hank pushed the plunger down, then removed the syringe and untied the tourniquet. Slowly Charles began to calm down. Even so, his tight grip on Erik's hand did not lessen. Movement in Charles' legs came back slowly, yet he continued to tremble and the tears still fell out of his eyes. It seemed, as he held even tighter to Erik's hand, that he could not choke back the sobs as they clawed their way out of him.
"Charles," Hank asked quietly, as if he believed that if his voice was to loud then would hurt Charles. "Would you like me to help you sleep?"
"P-please-" Charles answered, his voice breaking. He kept his eyes shut until Hank returned with another syringe full of a clear liquid. Charles watched, tears still steadily falling, as Hank stuck him and the clear liquid disappeared into his bloodstream. "Thank you, Hank." He whispered quietly. Hank smiled and patted Charles' shoulder lightly, nodding his reply. Charles eyes slid shut once again as Hank looked to Erik.
"He is going to fall asleep soon, you can help him back into the seat if you'd like." He told him quietly, before returning somberly to the cockpit.
Erik remained there, on the floor, with Charles as he began to fall into a drug-induced slumber. Charles shifted, using his legs, to curl onto his side. He buried his face into Erik's abdomen, his brow un-furrowing and shaking lessening. Still, his tight grip on Erik's hand didn't falter as he fell completely asleep, entirely at ease. Erik smiled lightly and used the sleeve his free arm to gently wipe the tears and blood from Charles' face. Once finished, he couldn't keep himself from running his fingers through that long chestnut hair as he leaned back against the chair behind him. Erik didn't miss the tiny smile that made its way across Charles' peaceful face in his sleep, making Erik's own smile grow as he watched Charles happily.