The lady--if that was indeed what she was--touched only the tip of her finger to the back of Arthur's hand. Her smile, sweet and sincere, drew out Arthur's most kingly frown, the one he wore when on the precipice of pledging himself and his knights (and Merlin) to another mad, hopeless, quest.
"I don't trust her," Merlin muttered in Gaius' ear as he bent to refill the cup Gaius had barely sipped.
Gaius cast a baleful look over his shoulder, but his hand was gentle on Merlin's wrist when he nudged the wine jug away from his goblet. "Merlin. You say that about every guest that comes through these doors for dinner."
"And when have I ever been wrong?" Now she had all four fingertips resting on the back of Arthur's hand, an unacceptable intimacy. Arthur's brow creased in discomfited confusion, but he did not take his hand away. To Merlin, it screamed loud and clear: sorcery. Since he had revealed his magic to Arthur some months ago, he would have thought Arthur would take his word for these things now. But, no.
He tipped the jug again, gaze still fixed on Arthur so that he failed to notice the wine splashing onto the table until he heard Gaius sigh. "Her father was a long-standing vassal of Uther's. Arthur has known her since childhood."
"Yes, and I repeat: when have I ever been wrong?" For all his wisdom and experience, sometimes Gaius could be, in Merlin's opinion, startlingly naive. Since the discovery that Gwen had gone off with Morgana quite of her own free will, Arthur's heart had become a desirable and vulnerable commodity. An endless march of hopeful brides had arrived as regularly as the cock crowed, and not a single one of them had intended to wait for Arthur to make up his own mind.
He mopped up the spill with his sleeve at Gaius' pointed look. When he looked over at Arthur again, his king was looking back with eyebrows lifted. Merlin shrugged. Arthur shook his head and then lifted his hand in summons.
"Lady Eleanor needs her cup refilled," Arthur said as Merlin approached. "If you can spare a moment from bathing the furniture, of course."
"Of course, my lord." Merlin grinned and with great pleasure pushed his way between their chairs, forcing Eleanor to remove her hand from Arthur's. As Merlin had expected, Arthur shook himself a little, as though clearing his head, and reapplied himself to his trencher.
Merlin poured the wine very, very slowly. As it trickled into Eleanor's goblet, he used the time to scan her fingers, arms, and--reluctantly--her décolletage for any items that could hold an enchantment. Her only adornment was so simple that he almost missed it, being more used to gaudy gems set with evil. A filament of copper circled her wrist, so thin it might have been no more than a twist of hair.
He angled his arm so that his wrist brushed against it. Instantly, she jerked her arm away, and Merlin's mouth tightened in triumph. The grasping little flare of magic had lasted only a second, but Merlin needed no more than that.
"Merlin." Strong fingers pressed into his other wrist, drawing his attention back where it always belonged. "We want to drink the wine, not swim in it."
Despite the acerbic words, Arthur was smiling. His smiles, oddly, had grown gentler since Gwen had left. Merlin smiled back, feeling himself gentle in turn. The wine reached the brim of the goblet, but had not yet spilled over.
"You've had plenty already, if you ask me." It was this, this that Gaius would never understand; why Merlin would do anything to keep his king safe, keep those eyes easy and untroubled. He had once trusted Arthur's heart to another. He would not make that mistake again.
"When have I ever asked you?" Arthur snorted, but rose from the table with a brief nod at Eleanor. "My lady, I bid you good night. Merlin?"
Merlin followed, though not before lifting his eyebrows at Gaius and nodding pointedly down at Eleanor's wrist. The strange filament caught the light as Eleanor started to reach out after Arthur before catching herself. Gaius tightened his lips and nodded back with resignation.
Winter had almost completed the long melt into spring, but the night air still chilled the skin. It should have been more than cold enough for Merlin to successfully coax Arthur into a warm nightshirt. Instead, Arthur brushed him away, flopping down onto his bed half naked and grinning as though he were getting away with something.
Merlin looked down at him and shook his head. "Fine, but when you start shivering, don't go calling for me to come warm your bed."
He had meant with the flat iron resting in the fireplace; when Arthur's mouth quirked, he fought not to flush. "Maybe I'll do just that," Arthur murmured. His eyelids had gone heavy with wine and sleep, but he reached up and tugged at Merlin's sleeve until Merlin sat down on the edge of the bed. "In fact, I think you'd best stay here tonight. In case I have need of you."
"All right." Merlin had not had any intention of straying out of earshot until whatever threat Eleanor posed to Arthur had been dealt with to Merlin's satisfaction.
Arthur's lips quirked further into a satisfied smile, as though he had won some kind of triumph instead of giving a simple command. Merlin narrowed his eyes and lifted his hand. But instead of the exasperated smack he had intended to mime until Arthur blocked him, he found himself resting his hand gently on Arthur's chest.
He expected to be batted away, knocked aside, told off for impertinence. He waited for Arthur to move, but when he did, he only put his own hand over Merlin's to hold it in place over his heart. Merlin's own chest tightened; he did not dare look at Arthur's face and kept his gaze locked on their joined hands. Arthur's heart thrummed under his palm. He counted the beats, each one a victory of Merlin's devotion.
At last Arthur sighed and released his hand. "See, perfectly warm," he said with an almost petulant note. He turned onto his side and closed his eyes, and Merlin's hand fell away. "Good night, Merlin."
Merlin stood and hesitated. He wondered what Arthur would do if Merlin simply climbed into the bed and settled himself down at Arthur's side, the better to guard him. It was not the first time he had wondered that; it was not the first time he had thought he might be welcomed.
But if he were wrong, Arthur would boot him out in a second, at least for tonight. When danger loomed, losing his place in Arthur's presence was a risk he could not take.
"Good night, Arthur," he said instead and let the intimacy of Arthur's name speak for the rest.
Merlin woke with a jolt on the cold pallet in the antechamber. Something was wrong. Something whispered from Arthur's bedchamber and set every hair on Merlin's body prickling with warning.
He bolted up and out, the cold stones under his bare feet clearing the last wisps of sleep from his mind. A single candle broke the darkness of Arthur's room, and in the flickering pool of light stood the Lady Eleanor next to Arthur's bed.
Arthur had turned onto his back in his sleep, and she held her hand up over his chest. Her delicate bracelet gleamed even in the dim light until it melted off her wrist forming a shimmering strand of magic that unfurled down to Arthur--and into his chest.
"Stop!" Merlin shouted and lunged forward.
Arthur's body slowly rose as though sitting up. A moment later, Arthur's eyes snapped open and he gasped, staring up at Eleanor in confused horror as the slender thread pulled him closer to her.
He could not let her touch him. That imperative consumed him as he sprinted across the room and launched himself across the bed. One hand pushed Eleanor away from Arthur while the other sliced through the magic thread to break the connection.
Eleanor crumpled to the floor like a broken puppet. Arthur fell back onto the bed, and Merlin fell across him. As he tried to catch himself, his palm pressed again to Arthur's chest.
A powerful jolt hit him, a shock that traveled up his arm and into his own chest. Arthur gasped beneath him. When Merlin righted himself, he was straddling Arthur's thighs, hand still caught against Arthur's breast. He stared down into Arthur's wide eyes--and then he was falling.
Falling, plunging, drowning, with nothing but Arthur to anchor him in the freefall. And it felt good, so good, so right, as though every need he had ever had was being fulfilled in that instant by the warmth of Arthur's skin, the heat of his mouth, the pressure of his arms. They were gone together, and Merlin felt nothing but bliss.
"Merlin!" Something had him by the shoulders, pulling him back, ripping him from Arthur. Merlin choked as he tumbled off the bed onto the floor. Arthur let out a cry of distress, and Merlin tried to scramble back up to him. They had been kissing, he realized, and they would both be all right if he could get back into Arthur's arms.
Icy water poured over his head before he could touch Arthur again. Merlin gasped and blinked against the shock of it, falling back on his hands on the floor. He looked up through the water dripping down into his eyes to see Gaius standing over him, an upturned ewer in his hands. "Gaius?"
Arthur fell over the side of the bed before Gaius could answer, struggling to get to Merlin. Even as Merlin reached for him, Gaius got between them. "Forgive me, sire," he said and planted his foot against Arthur's chest, heaving him back until he thudded against the bed frame. "Do not touch him again."
Merlin caught himself reaching again; he scuttled back until he hit the wardrobe. Magic, he realized as his wits slowly slotted themselves back into his head. This compulsion to get back to Arthur, lose himself in Arthur, become one with him in any way their bodies allowed, could not be anything else.
"Gaius," Arthur mumbled, shoving his fingers through his fringe as he looked between Gaius, Merlin, and the fallen Eleanor. "What the hell is going on?"
"This woman was attempting to enchant you, sire." Gaius watched them both warily. "Merlin suspected that the bracelet she wore had some sorcerous purpose. I spent the night searching for its meaning, but I had to go into the ancient folklore and I fear it took me too long."
Arthur looked across the room at Merlin with a dazed smile. "Good thing I kept Merlin tonight, then, isn't it?"
Merlin grinned back with equally dazed joy. Gaius did not smile, and abruptly Merlin remembered the magic. The thought had slipped from his mind under the weight of Arthur's eyes on him.
"Perhaps better than the alternative," Gaius was saying, frowning at both of them. "But I still fear I came too late."
"A heart thread." Merlin repeated the words. His mind felt clearer now that they were back in Gaius' familiar workroom. The struggle to get Eleanor down from Arthur's chamber and onto Gaius' bed had helped.
"Yes. Once cast, it cannot be taken back or destroyed. It appears that when you disrupted the connection, the thread attached itself to you instead."
Arthur sat at the work bench, face down buried in his arms on the table. "So another love spell? When will they stop?"
Merlin laughed at his aggrieved mutter. Arthur lifted his head to grin at him until Gaius sighed and stepped in between them.
"I'm afraid it's a good deal more than a love spell." Gaius laid the book he had been referencing open on the table and tapped the page. "A heart thread is a literal strand of magic from the fae spirit that dwells beneath the Hedryn Falls in Mercia. The lore contradicts itself whether the spirit is an exiled Sidhe, a fallen goddess, or something else entirely. The magic itself is well documented, though it has not been seen in centuries."
Arthur ground the heels of his hands into his eyes. "I don't care about the lore. What did this thing do to us and how do we undo it?"
"The lore matters, sire, because only the spirit herself can cut the thread once it has taken root." Gaius cleared his throat and looked away. "As for what it does. Once... consummated, the heart thread connects the caster and their subject in a powerful bond that cannot be broken by anything, not even death."
The words hung in the room for a long breath. Arthur stilled with his hands still over his eyes. "Once... consummated?"
Merlin could already feel his face burning as Gaius cleared his throat again and moved away, still carefully not looking at them. "The meaning is what you would expect, my lord."
Nervous laughter burbled up in Merlin's throat; his instinct to hide, well honed over the years, kicked in with ferocity. "Well, at least we'd never do that," he said and winced at the high pitch of his voice. "Would we?"
Arthur said nothing, but he dropped his hands and looked at Merlin. In his eyes, Merlin finally saw the truth that had long lain unspoken and ignored between them: that they would, and gladly, magic or no. With the magic, it seemed an inevitability that settled heavy and hot between Merlin's legs.
"Surely not," Gaius agreed with too much haste. "But the magic will do its best to convince you otherwise to fulfill its purpose."
"All right, so we go to the falls and get this spirit to remove this... thread, or whatever it is. Then everything can go back to normal." Arthur's eyes stayed on Merlin, a promise that normal between them had changed, and would change further if they both wanted it. He started to push himself up from the bench, but paused when Gaius shook his head.
"It cannot be removed, only cut." Gaius returned to his book and ran his finger down the page--to avoid looking at them, Merlin suspected as soon as he continued speaking. "That will break the effect, but the strands of the magic will remained anchored in your hearts. Should you engage in... amorous activity of your own volition, the bond would reconnect itself."
The words struck Merlin hard, and he shook his head in silent denial. To lose this feeling as soon as they found it, to go from someday to soon to never all in the space of an hour was more than Merlin could take in. All the heat in his body faded out.
Arthur looked as numb as Merlin felt. The muscle in his jaw worked as he dropped his head, still leaning on the table. When he looked up, his face had set into duty. "Then we have no choice. We'll ride for Mercia at dawn."
Fortunately, dawn was already near. Merlin did not know how much longer he could have sat there. Being in the same room with Arthur was torment, but being apart from him was impossible, as they discovered in humiliating fashion in a stairwell.
They rode fast; the Hedryn Falls lay over a day's ride away and they could not afford to dally, in any sense of the word. The surge of the horses and the thunder of their hooves made conversation impractical--but Arthur could manage to shout at him under any circumstances.
"You couldn't have just hit her over the head?" he yelled. "Like any normal person?"
Merlin glowered. "Any normal person would stop letting lovesick nobility with magic jewelry in the damn door," he shouted back.
"What sorcerer just jumps into the middle of a magical attack?"
"Believe me, it won't happen again on your account."
It went on like that until eventually they had to slow the horses to let them catch their wind. Now that speaking was easier, they fell silent. All the things Merlin wanted to say had no meaning now. Whatever feelings he had, whatever feelings Arthur might have shared, they had come too late to the realization of them.
"Merlin? Merlin!" Arthur's voice jolted him back to awareness, but not in time to keep him from sliding out of the saddle into a heap on the ground.
He shook off the shock of the fall just as Arthur jumped down and crouched beside him. "What happened?"
"I think I should be asking that question." Arthur reached out a hand to check Merlin's head. Merlin's scalp tingled, craving more of his touch. "You just started leaning towards me, more and more until I realized you weren't going to stop."
"Right. I don't remember that at all." But he could guess what had happened: he had gone so deep into thought that the magic took its opportunity to pull him towards Arthur again.
From the way Arthur swallowed, Merlin could see he had made the same deduction. "Well," he said. "If I can't trust you to stay on a horse, you'll have to ride with me."
Wise or foolish, Merlin found himself unable to disagree. He climbed up behind Arthur and made no pretense of trying not to touch him. If they were to gallop, he would have to wrap his arms around Arthur anyway, and he felt something in him ease as soon as he was pressed to Arthur's back. Still, he wished Arthur had worn his chain mail. The softness and give of his padded jacket made Merlin need both more and less separation between their skin.
They left Merlin's horse at an outpost and rode north. Merlin had been half hard since they left Camelot, and now his cock prodded at Arthur's backside like it thought it could get in if it tried often enough. Arthur refused to acknowledge what he could not have helped feeling, but Merlin knew well enough without feeling it that Arthur was no less aroused.
Even at full speed, the double burden meant they made slower progress. Night fell when they were still more than a league from the falls. At last even Arthur had to admit defeat and stop for the night. They worked together in silence to build a fire and dole out their cold supper, and Merlin stayed silent as the fire crackled between them.
"I never could figure out what you were to me." The quiet words made Merlin jump as though Arthur had shouted them. "For a long time, I convinced myself it didn't matter."
"What else could we be?" Merlin mumbled back. Prince and peasant, master and servant, destined king and secret warlock--that should have been enough for one lifetime.
"Then Gwen left, and I realized it mattered very much." Arthur was staring into the fire; when he lifted his head to look at Merlin, his eyes sent a shiver through Merlin's body that had little to do with magic. "But I thought we had all the time in the world to figure it out."
"We never have as much as we think." And Merlin had always been so good at wasting it. He stretched it out now, holding Arthur's gaze and letting the pull between them build, letting the heart thread tighten until Arthur dropped his head again.
"Good night, Merlin," he said and lay down on his bedroll.
"Good night." Merlin stretched out on his back and closed his eyes. At least in sleep, he could escape both the compulsion and his regrets.
Everything felt so good in his dreams: Arthur's breath hot on his face, Arthur's cock heavy and hard in his mouth, Arthur's weight pinning him down. Merlin moaned with an abandon he could never give himself, or Arthur, in the waking world.
Then his eyes blinked open. He was not dreaming. He lay on his bedroll, naked from the waist down, and Arthur lay atop him, fully naked between his thighs, the head of his cock just starting to penetrate.
Merlin gasped as his body gave way to the thick push of Arthur's cock. Above him, Arthur's face was slack with sleep and pleasure both; his eyelids fluttered in his own waking dream. "Arthur," Merlin said, the name broken by a groan as Arthur's cock pressed into Merlin's prostate. He reached up and gripped Arthur's shoulders, but could not summon either muscle or magic to throw Arthur off him. "Arthur, wake up. You have to wake up."
Arthur had buried himself to the root, tight balls pressing against Merlin's arse, before his eyes finally opened. "Merlin?" he slurred, drunk with sleep and the consuming pull of the thread.
"Arthur, you have to stop." He made to push Arthur back, only to find himself pulling Arthur closer. At least his words still obeyed him. "We can't finish this, or we won't be able to cut the thread."
"Oh, God." Even as his eyes widened with the consciousness of what they were doing, Arthur's hips surged in another thrust. "Oh, fuck, fuck. Stop. We have to stop."
Merlin's hips pushed up to meet him, making them both groan in frustration. "Just--just stay still for a minute. We have to--oh, oh, no, don't do that. We have to get control of this."
Arthur rocked into him a few more times before he finally stilled, face scrunching with the effort. Though he was still fully sheathed in Merlin, he relaxed a little after a moment and looked down at Merlin with a frown. "Did I--am I hurting you?"
"No. Er, quite the contrary." Merlin choked back a laugh. Arthur's cock had moved in him with a sure, sweet glide, far from dry. When Merlin smacked his lips, he could taste cock. "I, er, I think I may have sucked you, beforehand."
And probably added a little something extra, whether from his own magic or the effects of the heart thread. Arthur grunted, closing his eyes against the image. Merlin felt the tremor that went through him.
They stayed still for long moments, not ready to risk moving enough to separate. Arthur kept his eyes closed, and Merlin knew he should do the same. The sight of Arthur naked above him did little help calm him.
"I think we need a plan for how to do this," he said when he had a minimum of control back.
Arthur's throat worked in a swallow before his eyes opened, dark in the dim light of the dying fire. "We could just let it happen," he whispered. "We could just... finish this."
Merlin had to close his eyes at that, but even so, his hips pressed up without his permission to increase the pressure of Arthur in his arse. "Not like this," he forced out, though he badly wanted to agree. "Not like this."
It took almost until dawn to extract themselves from each other without triggering a resumption of their involuntary lovemaking. It hurt when Arthur pulled out, still rigid as steel. "I don't suppose...," he mumbled, hand straying toward his straining cock.
Merlin was equally hard, but shook his head. "I don't think we should risk... any form of, er, completion right now."
"Right." With a pained grimace, Arthur reached for his trousers. The bottoms of the legs were scorched, as were his boots. In his sleep, Arthur had walked through the fire to get to Merlin. "We'd best go anyway."
Merlin heard the soft roar of the falls before he saw them and sighed with relief. Riding together had proved impossible, and his feet were sore. "So what do we do?" he said as they hiked up the final incline. "Bring an offering? Beg?"
Arthur's hand strayed to his sword hilt. "I'll stick with what I'm good at."
He rolled his eyes, but stuck close to Arthur's shoulder as they slide down the slope to the river bank and made their way up to the falls. A narrow path started close the rock face and led into the mist behind the cataract.
As soon as they entered the dim cavern under the falls, the sound of the water abruptly cut off into silence. At the same moment, Merlin felt the pressure ease inside him, as though the thread had gone slack now that it had come back to its origin. Arthur let out a short breath as though similarly relieved, though the tension remained in the set of his shoulders.
"Hello?" Merlin called, and Arthur threw him an exasperated glare over his shoulder. "Anyone here?"
His words echoed up into the high arches of the cavern and back down to their ears. No other sound answered him, but he felt a chill sweep down him. The cold mist drifting over them could not account for it.
Arthur advanced with his usual flare of caution and boldness. Merlin followed him for a few paces, but stopped as another chill raised the hair on the back of his neck. The mist seemed to twine around them, and Merlin felt as much as heard the voice that swirled within it, no more than a breath against his ear.
If you have come for a thread of my heart, there is nothing left of me to give.
"No," Merlin answered quietly, an unexpected sadness weighting his words. Ahead of him, Arthur turned with a puzzled frown. "We have that, but it was done to us against our will. We've come to ask you to undo it."
The mist rose high above them, dispersing until only a shimmer remained. It formed the shape of a woman, or something that might once have been a woman before she lost everything that held her together. Faint arms, or wings, stretched around to either side of them. Arthur moved closer to Merlin, never taking his eyes from the gathered mist.
"Can you cut it?" he asked, wary, unhappily resolute.
You ask for too much. You are bound by many threads. Love. Magic. Destiny. Mine is but the final thread that seals the rest, and much less powerful.
"But it isn't real," Arthur gritted out. "It isn't our choice."
Choice is illusion, Arthur Pendragon.
Merlin looked up at her, filled with a strange pity, but resolute. In the matter of his heart, in this one thing, Arthur would always have a choice; Merlin had fought greater battles than this to see to it.
He let the magic flare in his eyes. "Nor are we offering you a choice. Whatever else binds us, this thread is yours and you will sever it now."
Her presence flowed around him; he felt her anger, but heard her laughter. He had no time to make sense of it. As if caught in a sudden, violent wind of its own creation, the mist swirled up to the top of the cavern. It solidified into a thin, gleaming blade. Then it swung down between them, and Merlin had time for only a single gasp of apprehension before he fell to the ground, stunned.
When he recovered his senses, he pushed himself up on his elbows and looked for Arthur. His king lay crumpled an arm's length away, but he groaned and pushed himself up before Merlin could call to him. He pulled himself over to Merlin and fell against his side.
"Well, that's done," he said, and they lay in silence for a long time.
Spring had taken firm root some days ago, but the nights still cooled enough to make Merlin shiver. As he knelt to tend the fire, he congratulated himself on finally persuading Arthur into a night shirt. It helped that smoothing it over his shoulders was an excuse to touch him, a rare indulgence since their return from the Hedwyn Falls. The thought made him jab harder at the kindling.
"Merlin. Leave it."
Merlin stood and turned, but his grumpy protest fell off his lips unvoiced. All his work in securing the night shirt had gone for naught, for there stood Arthur next to his turned-down bed, as naked as if Merlin had never clothed him at all. "What are you doing, Arthur?"
"Making a choice," Arthur said, then gave a small laugh. "Though I don't think I've ever had a choice, when it came to you, have I?"
Merlin's lips twitched reluctantly. "I make better choices than you do, anyway."
"Debatable," Arthur shot back, smile widening. He sobered after a moment and held out his hand. "But I'm asking you to make this one now."
Merlin pulled in a shaky breath and closed his eyes against the lure of Arthur's offer. Already he could feel the stir in his heart where the severed thread lay dormant. "You know what will happen if we do this. Do you really understand what you're asking?"
"Yes. And I won't say that it doesn't terrify me, a little bit. But I understand what you are to me now." Arthur stopped, but Merlin felt the unsaid conclusion rise up from within him: everything.
His body was already responding to his desire to accept Arthur's proposition, encouraged by the hopeful magic. "You can never marry."
"I never intended to." Arthur was still smiling when Merlin opened his eyes. "Come now, Merlin. We're already bound to each other in this life and the next, aren't we? And if we weren't, I'd have it so."
So would Merlin, if he had ever had any doubts, any choice about where his heart was given. He took a deep breath and let go, letting the sudden joy spill out as laughter. "All right. Let's make sure of it, then."
He walked to Arthur and took his hand, let Arthur pull him into his arms. The heat of Arthur's naked flesh through his clothes, the half-hard cock against his thigh, made him press closer to ease the ache of desire. He let his lips brush over Arthur's shoulder, his teeth graze Arthur's neck, his tongue daub at Arthur's jaw.
Then he found Arthur's mouth properly and sealed both their fates. They kissed, deep and hungry, even as they pulled the clothes from Merlin's body. Arthur tore the front of his tunic from neck to navel rather than give up his mouth. Still kissing fiercely, Merlin dropped his arms to let Arthur push the ruined garment off his shoulders and manhandle him onto the bed.
Only when Arthur had Merlin spread beneath him did he break away from his lips. Dazed, Merlin looked up at his glazed eyes, flushed cheeks, swollen lips. "Do you feel it?" Arthur demanded, bending for another kiss as if to slake a thirst.
"Yeah." Merlin groaned and arched his body into Arthur's. He felt it, the stirring, the unfurling, the magic engorging with his heart's blood. "Arthur, we won't be able to stop much longer."
"Is that a warning or a promise?" Arthur did not wait for an answer before pressing back into Merlin's mouth. His hands began a heated, hesitant exploration of Merlin's body. When his fingers brushed over Merlin's thighs, urging them to part, Merlin finally let himself give in.
As soon as he did, the ache turned to pleasure. Arthur's body writhed under his greedy hands as Merlin writhed beneath him. He let Arthur prepare him slowly, even as his heart pounded in his chest, eager to have it done.
Arthur's heart also must have pounded, but he moved with purpose over Merlin's body, denying the urgency to be moving inside him as well. When they were both gasping against each other's lips, when Merlin was aching and open, he shifted to roll his hips up, lifting his legs up and apart.
It brought his arse into position for Arthur to push into it. Arthur groaned, helpless to do anything else. As his cock sank into Merlin's flesh, Merlin sighed with a bone-deep relief. This time, he did not have to fight it. This time, he could let Arthur spill inside him and let the magic take its course.
Arthur's eyes fluttered shut as he began rocking into him. Merlin pressed his palm against Arthur's heart and let his own eyes close as well to savor the joining of their bodies. Every thrust, every grind of Arthur's cock into his body, tightened the thread rebuilding between them and brought him closer to the final moment they had chosen.
"Merlin." Arthur stuttered his name as his hips moved faster, urgent. The magic would wait no longer; nor would their bodies.
Merlin choked against the pleasure as his climax swelled up to meet him. His fingers dug into Arthur's arms as his body jerked with every pulse. Arthur let out one more low moan, and then warmth suffused Merlin's belly as Arthur's release filled him. At the same moment, the invisible thread tightened one more time between them, a powerful jolt of pain and ecstasy.
Then it faded as though it had never been there at all. Arthur sagged over Merlin's body, panting against his cheek, cock still driven deep. Merlin tried to embrace him, wound up mindlessly caressing him, and finally went limp with exhaustion.
Arthur slipped from him after a short while, letting Merlin's legs fall around his waist. When Merlin opened his eyes, Arthur was frowning. "I don't feel any different," he said.
Merlin sat up, pulling himself out from under Arthur enough to run his hand down the front of his body. "I don't, either. Aside from your come in my arse," he added, and grinned at Arthur's flush.
Arthur wrestled him to the pillows for that, and Merlin resisted only because it felt good to push back against Arthur's solid limbs. When Arthur finally pinned him with a wide smile of victory, Merlin's skin felt alight again. He pulled Arthur the rest of the way down to him, and pressed his mouth to Arthur's ear as their bodies began moving together once more.
"Maybe it's like she said--we're already bound to each other," he murmured as Arthur settled into the cradle of his hips. "So this... just is."
"It just is," Arthur agreed against his throat, but then frowned. "Merlin, that makes no bloody sense."
Merlin shrugged. Then his legs wrapped around Arthur's thighs and his hands found Arthur's arse, and soon everything made sense enough for them.