Arthur is having a hard time with his sword arm again. Merlin can see right through him, and Arthur knows it too. But he still tries to hide it, being the prat that he is. Arthur had injured it a long time ago from overuse. Merlin had tended to it himself, but no matter how well he mended it, it couldn't be completely fixed in the long run because Arthur still insists on picking up a sword. Merlin licks his lips, torn between his concern for Arthur and his concern for the kingdom.
"I know what you're thinking," Arthur says suddenly, not even turning to look at him.
Merlin rolls his eyes. "And what, pray tell, might I be thinking, your majesty?"
Arthur turns this time, his expression an odd mix of amusement and weariness. "You don't want me to fight."
Merlin crosses his arms with a sigh. "It's not that I don't want you to fight. I know you will, no matter what. It's just—"
"What?" Arthur interjects, his tone challenging.
Merlin sighs exasperatedly, his hands falling back to his sides. "You can't defend yourself as well as you used to. If we lose you in battle—"
"I can defend myself just fine. Besides, I'll have you right there with me, won't I? My good luck charm."
Despite the worry churning within him, Merlin is unable to suppress a smile. "Of course. There's nowhere else I'd ever be."
Arthur grabs Merlin's wrist, pulling him close. Merlin's breath hitches, as if this is the first time Arthur's done so. The king plants a kiss on Merlin's open lips, leaving him all the more breathless for a moment.
"Stop worrying like a starry-eyed maiden. King's orders."
"You know I can't help it after all the times I've had to save your sorry arse."
Arthur bites Merlin's lip in retaliation, his brow arched mischievously. Merlin just lets out a laugh, which was cut short by Arthur's lips effectively silencing him.
"You were always destined to be a pain in my arse, weren't you?" Merlin whispers, his eyes peering up into Arthur's.
"You love me anyway."
Merlin nods. "With all my heart."
…
Arthur's got grey in his hair. It's only a bit, but Merlin notices it when he kisses his golden head in the lazy hours of the morning. At first, Merlin teases him, calling him a wise old king. It's only late in the night, when Arthur's profile is illuminated by the crackling hearth that Merlin lets slip that he likes it. His king smiles victoriously, pouncing on Merlin, who never stood a chance, rendered helpless by the blankets cocooning him. Merlin voices his disadvantage, but his protests fall on deaf ears as Arthur kisses up the length of his neck and then slows, settling on his jaw. The hearth burns brighter as Merlin's magic hums in the air, responding naturally to mirror his pleasure. Arthur stops, pulling back just far enough to smirk.
Merlin groans with feigned annoyance. "Must you always be so smug?"
"Yes. It's one of my many admirable traits."
"You wish," Merlin says, freeing one of his hands from under the covers. He lifts his hand to Arthur's nose, flicking a harmless orange spark at him from his fingertips.
Arthur bats it away with an undignified hey and Merlin is laughing before the king can figure out how to enact his revenge.
….
Merlin's hair is as dark as ever. Initially, the warlock had known that he was younger and therefore would take a bit longer, but years had passed and he's still the same. He notices the subtle changes in Arthur—his gait, posture, voice, and weariness. But more than anything, Merlin notices how these changes don't take place in him. Merlin grows more and more frightened on what it could mean, but he doesn't allow himself to dwell on it. He knows Arthur has noticed, but he doesn't say anything about it either.
…
"You're so beautiful."
Merlin doesn't quite know why, but he flinches at the words. Arthur's touching his face, staring wistfully into his eyes. His blonde hair is entirely gone now, chased away by silver. His eyes crinkle in the corners with mirth.
"I remember the first day we met, all those years ago. I thought, how can anyone on this earth actually look like that?"
"Ears weighing down my entire body?" Merlin says, a lopsided smile pulling at his lips.
Arthur huffs out a laugh, but it quickly subsides into a melancholy smile. "You look almost exactly the same."
Dread settles in Merlin's stomach, making him ache. He presses his right hand over his eyes. "I'm so scared, Arthur," he whispers, feeling his eyes grow wet under his fingers.
Arthur gathers Merlin up in his steady grip, pulling him onto his lap. Merlin curls up into a ball, feeling utterly small as the tears keep falling. His heart is racing, his breath stuttering as the truth they'd been dancing around so carefully suddenly opens up under them and threatens to swallow him.
"I don't want to be alone," Merlin says into Arthur's chest. Maybe it's selfish to say, but it's so true it hurts, cuts him to his very core.
"I'm sorry, Merlin. You deserve so much better. I wouldn't wish this upon my worst enemy."
And Merlin breaks, sobbing openly in Arthur's arms, knowing that even this moment is fleeting for him.
…
It happened in the night. Merlin felt it, the tug to wakefulness before it hit him. Even as dawn breaks, Merlin remains, stock-still. The tears had dried out long ago, his voice nearly gone with them. Arthur is so still in Merlin's hold. His only warmth now comes from Merlin's magic, digging its claws into him as if it could bring him back. Merlin had known it was coming, but that never made any of it hurt less.
How is he expected to continue? Merlin's entire world is gone, ripped away in the quiet hours of the night. There's nothing left in him that wishes to carry on.
They find him there, eyes unfocused and body rigid with the shock of it. It takes more than one of them to pry Arthur out of his grip. They're saying things to him, touching him tentatively. He barely notices any of it. He just sits, staring at his horribly-smooth hands. Not a single wrinkle or mark of old age. He's never been more disgusted with himself.
…
They give him a proper funeral fit for a just king. Merlin can't bring himself to go. He can't say good-bye, can hardly think it. He leaves Camelot that morning before the sun begins to rise. He momentarily considers heading towards Ealdor, but the thought of his mother, of Will, quickly turns him in the opposite direction. Merlin has nothing left, no one to turn to. He's outlived everyone that ever mattered to him. To other men, perhaps this would be seen as a victory. To Merlin, it is the worst possible fate ever bestowed on a man.
He wanders, perhaps for days. He doesn't really keep track. No food or drink ever came near his lips as he walked. Merlin's body finally fails him, crumpling to the ground in a heap. He moves onto his back, staring up at the bright sun and the cloudless blue sky. How dare the world still boast such beauty and cheeriness after everything?
Merlin lies there in the grass, unsure and uncaring of how much time has passed. His magic starts to hum within him, slowly at first and then all at once. Merlin feels it seeping into the earth, as if returning to it. He wonders distantly if this might be the thing to finally kill him, and he can't bring himself to care. As his eyes flutter closed, he sees life springing up all around him.
At least he has one last thing to offer before he's gone.