A/N: Title comes from "Elegy" by Dylan Thomas. First time writing these characters, so I apologize if anyone is out of character.
Merlin picked up the cloth out of the hot water and gently ran it down Arthur's arm, wiping away sweat, dirt, and blood; it pained him to see the latter, although he was grateful that it was not all Arthur's. He repeated the motion, keeping the touch as light as possible as he scrubbed all of it away, revealing bruised skin. He saved this cloth for times like these, the threadbare scrap so worn and soft that he had needed magic just to keep from falling to pieces altogether. He wished he could do the same for Arthur.
He repeated the motion on the other arm, nudging Arthur to lean the other way for the moment. The Crown Prince of Camelot had said little since his return, but Arthur had said nothing all night, and Merlin knew he wouldn't. Silence tended to make Merlin nervous and want to fill it with mindless babble, but he respected it this time and kept his mouth shut.
The scent of lavender drifted up from the bath water and his clothes. He had rolled up his sleeves, but water went where it wanted to, and had made a slight mess of his shirt and pants. He didn't care, because even with all of the lavender he had put in he could still smell the pungent blood that swirled in the water. He had added it in hopes it would help soothe Arthur, but he wondered if it was in vain; it would help with the ache in Arthur's body, but there was no taking the pain out of grief.
He nudged Arthur forward slightly to wash his back, and although he could understand it and even respect it, the quiet compliance frightened him. Arthur had become a ragdoll before him, barely a ghost of his usual self. The deadened look in his eye had made Merlin want to grab him and shake him, or yell at him, or perform some stupid act of magic right in front of him, anything to get a response other than silence and submission. He had only refrained from doing so because he had known what that look meant and hadn't been sure Arthur would have ever forgiven him if he had.
Arthur hissed as he pressed too hard against strained muscle. Merlin winced and stopped his motion, hoping for an insult about his lack of skill or a complaint of his general uselessness, but there was nothing more, and he wanted to scream. Arthur was in pain, and it wasn't a pain he could heal with magic or any of Gaius's elixirs or even just by being his usual clumsy, ridiculous self that nearly always made Arthur laugh or at least roll his eyes towards Heaven with an expression of affectionate exasperation. He was to help and protect this man and here he was, genuinely useless. He closed his eyes, his hand curling into a fist and wringing the water out of the cloth. Arthur made a low noise, a half-keen and half-growl, as the hot water ran down the bruises on his back. Merlin opened his eyes and gave Arthur a closer look.
He was hunched up, his knees slightly bent; he was leaning forward and against the side of the tub, his shoulders fallen. His wet hair hewed to his head and the back of his neck, darkened by the water and the stain of blood that would not wash out. The broad, tan body was mottled with bruises and minor cuts, a palette that made Merlin ache just looking at them. Arthur slowly turned his head to look back at Merlin, his face nearly as marred as his back, and made his blue eyes stand out so much more sharply. His expression was mostly blank, but Merlin could see the red of his eyes; the feeling of complete uselessness hit deeply. He had do something, anything, and a memory of his mother kissing his childhood injuries and holding him safe flitted through his mind. Before he could really think about what he was doing. he bent down and placed a feather light kiss against Arthur's back.
There was a quick intake of breath that Merlin barely heard, and when he glanced up, he saw Arthur mouth his name, his eyes closed. When they opened again, the blue was filled with a broken longing that Merlin nearly lost his own breath. Without looking away he stood and began stripping himself bare; in the few seconds it took Arthur has inched his way forward, giving Merlin only just enough room to step in behind and slide down until he was sitting behind Arthur. He reached forward and pulled Arthur towards him, back to chest, and then carefully wrapped his arms around him. Arthur rested his head on Merlin's shoulder, face turned inward, and Merlin kissed his forehead. One of Arthur's hands grasped his, holding it tight and saying all that he couldn't. Merlin held tight as well, vowing to himself that he would never let go.
"I got you," he whispered. "I'm here, and I've got you, and I'm not going anywhere."