Merlin slides to his knees at Achlys's feet. Soft clouds of fog billow upward at his descent, then, as the young man chokes out one more pleading word, he falls to the ground. The mist settles on his body, obscuring it from view. From where Arthur stands, he can see the way the fog drifts up and over Merlin's prone body, a strange mound forming in the mist. Like overturned earth covering a corpse.
It looks like a grave.
Arthur's throat feels bloody and raw. He tastes copper in his mouth. Distantly, he thinks he must still be screaming, but all sound is lost beneath the roar in his ears. All feeling is eaten by the sudden emptiness that surrounds him.
It's happened before–Merlin has disappeared, laid on his deathbed, struggled to breathe and continue on–but never before has Arthur felt so bereft. Something deep in his chest is missing.
Merlin is dying, close to dead, and Arthur can't get to him. Merlin, impossible Merlin, immortal Merlin if the creature is to be believed, was killed by that thing standing just a heartbeat away.
Arthur has never before wanted to kill something so badly. It feels like a need, an insane compulsion. Every rational thought has been driven from his mind. His body seems to act on its own accord, hacking and slashing and beating against the invisible boundary that lies between him and his enemy. Between him and Merlin's body.
This is what desperation feels like, a remote piece of Arthur recognizes. This is what terror is. Everything else before this has just been paltry fear. Nothing.
His hands, calloused and scarred from years of weapons training, tremble. He can't keep a proper grasp on his sword, but he swings it anyway. Every muscle and tendon in his body shakes with the effort of keeping him together. Sweat and tears course down his face.
Time inches by. He could have been there for minutes or hours.
Achlys finally raises its head to look at him. It is the first time it has acknowledged Arthur, and the motion sends the king into even more of a frenzy. He's spitting, shouting, cursing, throwing himself forward with all of his remaining strength, channeling the insidious worry and grief that has settled into the marrow of his bones toward getting through the barrier.
"I'm sorry," Achlys murmurs. "But he couldn't go on like that."
"You made him like that!" Arthur screams. "You put him through hell and have the audacity to call it mercy when you take his life?"
Achlys blinks. Then, it says, "I have known you your whole life, Arthur. But I know him better. And it broke my heart to see what Existence has in store for him."
"You're a monster," Arthur growls. The fight leaves his body, and he finds himself standing alone, in the cold. His eyes betray his reason and fall once again to the raised fog at Achlys's feet.
"I am sorrow, misery, and death," Achlys says sadly.
"You took him from me," Arthur says. His voice does not stray above a ragged whisper. "And you are still keeping me from him."
A beat of silence passes. Then, something changes. Something about the air pressure, or the temperature, or perhaps it is simply that the knowledge that where there had once existed a barrier between the them changes into a knowledge that it is no longer there, but Arthur can sense that he can move forward now.
Toward Achlys. Toward Merlin.
Arthur's gaze snaps up from Merlin and back onto Achlys. The king's grip on his sword, still too weak for what it should be, strengthens somewhat. Achlys shakes its head.
"That is the sword Merlin made for you," Achlys says, inclining its head toward Excalibur.
Arthur's heart twists and cinches. He finds his familiar grip again, some strength leeching back into his fingers at the reminder of his friend. Though he knows he should question the creature–after all, Merlin himself had told Arthur this sword belonged to a legendary king, and it had been found in a stone for the gods' sakes, there's no way Merlin made it–he doesn't make a correction. Something about the words ring true. Wielding the sword brings the same kind of surety to mind as if Merlin were at his back. It is comforting. Secure. Nothing could harm him, not while Merlin and Excalibur are in his favor.
But Merlin is on the ground, bleeding from his throat, hidden beneath the fog, and Arthur's grip on the sword is weaker than it had been when he was just five and made to heft the dulled practice blades on the training grounds.
"It is a fine blade," Achlys continues, staring at it. "It can kill the immortal, you know. He forged it in dragon's breath just for you, from a blade originally crafted by Thomas Smith. It knows no equal and recognizes no other master. The only sword fit for the Once and Future King."
"Fitting, then, that it will be his blade that will end you," Arthur says. His voice is not strong enough for his liking, still thick and slow, raspy with the echo of his screaming.
He takes a step forward. His imagination briefly flashes a vision through his mind, the image of Merlin's slight body holding the sword aloft before the terrible beast that is a dragon, allowing its flames to lick along the metal. It passes as soon as it arrives, and Arthur cannot bear to call it forward again. There are too many questions that accompany it. Too much pain.
"No," Achlys says. "Even Merlin's sword cannot kill me."
It steps forward then, showing Arthur the blade it had used on Merlin. The horrible thing that could rend flesh apart with a single touch. Sephtis, it had said. Eternal death.
Achlys swings the blade around so the hilt faces Arthur.
"This one can," Achlys says softly. He lifts his arm, offering the blade to Arthur. "Do it. Send me home."
Arthur stares hard at the blade for a split second. Then, his eyes turn back to the small mound of fog swirling in the place where his friend's body had fallen.
"Do it yourself," Arthur snaps. Excalibur falls from his hand and he dashes to Merlin's side. As he collapses on his knees next to his friend, the fog lifts and parts.
Merlin's body looks… ruined. Blood coats his mouth, neck, and chest, spattered along his jaw where he had coughed out words amid the bleeding, running in rivulets past his ears and into his hair, soaking into his thin clothing. It's too hot and too real against the eerie cold and desolation of the cavern. A long, deep cut has sliced through his jugular, almost to the back of his spine. It's a clean cut. If it had happened quickly, Merlin may have been spared pain.
But Arthur had watched it happen. And true to Achlys's word, it had been slow, painful, and terrible.
Somehow, all this time, Arthur had held onto hope. Merlin had escaped worse odds before, hadn't he? He had consumed fatal poison and lived. Disappeared for days on end and turned up without a scratch. The Dorocha's touch couldn't harm him, a swinging mace or sword could put him down but he always got back up. Always.
"I'm sorry," Achlys says again.
Arthur does not watch to see as the creature plunges Sephtis into the space in its mist-form body where a stomach should be. Its eyes glow brighter, then dim into nothing. The blade of Eternal Death clatters to the floor, where it seems to simply melt into nothingness.
Arthur cannot bear to look at Merlin and cannot bear to look away. Merlin's wound still weeps blood profusely, drenching his clothes and pooling on the floor. But his chest is still, devoid of even the barest movement hinting at lungs expanding and contracting. And his eyes. Those eyes so quick to smile, so full of unknowable depth and surprising wisdom, they're open. Glassy. Unmoving.
Arthur's breath catches in his raw throat. He leans forward, fingers twitching toward Merlin's body. Then, just as he is about to touch the younger man, he throws himself violently to the side. He lands on his hands and knees and retches painfully into the dark fog.
It takes him longer than he would ever admit to stop the dry heaving. When his body finally calms enough to allow him to get back onto his knees, he forces himself to look at Merlin again.
His tears are scalding, sluicing down his cheeks unchecked. He watches, numb, as they fall on Merlin's bloodied neck.
"Merlin," Arthur murmurs. He knows it comes out as more a whimper than anything else, but he can't help it and he doesn't care, damn it, because his best friend…
His best friend is dead on the ground in front of him. And Arthur didn't stop it from happening. He should have stopped it.
Arthur leans forward, hands trembling like leaves in the wind. His spine is alight with nerves, his head heavy and filled with fog like the mist that surrounds them: dark, impenetrable.
He gently places a hand behind Merlin's head, ignoring the heat and stickiness of the blood there. He wraps his other beneath the young man's back. With great care and a kind of gentleness that usually escapes him, Arthur pulls Merlin's body to his chest. He takes great pains to avoid moving Merlin's neck. He avoids looking anywhere but at Merlin's face, mouth still open, eyes still gazing with horror at nothing.
Arthur kneels on the cold stone ground, Merlin's blood soaking into his shirt. Merlin's body is still warm, but grows stiffer by the second as Arthur cradles him. A low keening comes unbidden from deep in Arthur's chest, which grows to gasping, choked sobs.
Of course, Merlin would do something so horribly stupid just to prove Arthur wrong. Of course, there is a man worth his tears.
Arthur sits alone in the cavern and sheds every last one for his brother.
The knights arrive sometime later. Leon and Elyan come first. The stand at the entrance to the cavern in the same spot where Arthur had been trapped earlier. Neither approaches the king and his manservant. If both of them shed tears for the dead man, neither makes it known. They simply take up vigil in the dim grey of the cave and bear witness to Merlin's death and Arthur's grief.
Percival arrives shortly thereafter with Mordred, both supporting a weak but fierce-eyed Gwaine.
Mordred breaks away first, his stomach twisting and dropping to his feet as Arthur's cries reach them. He stumbles forward, past Leon and Elyan, and drops to his knees next to his king. Arthur's only reaction–the only thing that makes the knights think he is aware of their arrival–is to pull Merlin in closer.
"Is he…" Mordred begins.
Another sob rips through Arthur. It is the only answer Mordred receives. The young knight lowers his head, tears dripping onto the ground.
"No," Gwaine says. He shakes his head resolutely, eyes never leaving Merlin. "No, he–he wouldn't."
"Gwaine–" Percival says, keeping a strong arm around the roguish knight.
"No," Gwaine repeats, stronger this time. He pushes himself away from Percival, standing on unsteady legs. "He wouldn't. He's stronger than that, stronger than anyone. He wouldn't just give up!"
"He didn't give up," Arthur says. His voice sounds like broken glass. "You're right, Gwaine. He wouldn't do that."
Arthur looks down at Merlin. The knights are quiet for a moment.
"But he's gone anyway," Arthur finishes. "I failed him. Achlys took him and now he's…"
Gwaine shouts and surges forward, as if letting Arthur finish the sentence would make it true. Percival and Leon try to hold him back, but it's no use. Gwaine falls to his knees next to Mordred and in front of Arthur, his hands reaching out for Merlin's body.
Arthur finally relinquishes his friend and sits back, staring numbly as Gwaine cradles his best friend's ruined body.
Some part of him is relieved that he didn't finish his thought, that Gwaine interrupted him before he could speak truth to their reality. Another part feels that it simply is another betrayal of the manservant, to not even utter in full how Arthur had failed to protect him.
"Arthur," Leon says quietly, "where is Achlys?"
Arthur's eyes flick up to look at Leon. The head knight shifts uncomfortably. Never before had he seen the king's gaze so… so empty.
"He followed Merlin," Arthur replies.
They are quiet for a long time, allowing one another to sit with Merlin's body and their grief. After a while, Mordred quietly takes off his red cape. From the skein on his side, he pours cold water onto the cloth until it's wet. Without trying to remove Merlin from Gwaine's tight embrace, he uses gentle hands and soft movements to begin wiping away the blood that still paints the young man's pale skin.
"Camelot," Arthur says softly.
"Not yet," Gwaine says, looking up at Arthur with wide, pleading eyes. "Not yet. There must be something–"
"No, Gwaine," Arthur whispers. "It's done."
Gwaine squeezes his eyes shut, more tears falling. He bows his head over Merlin, his shoulders shaking violently with quiet sobs.
Arthur eventually picks himself up from the ground. Mordred has quietly wiped away most of the blood from Merlin's face by the time the young knight had done so. The druid's hands shake as he moves toward Merlin's neck.
Arthur puts a hand on Mordred's shoulder, stopping the young man before he can continue. Mordred looks up at his king, green eyes swimming with tears, face twisted with disbelief and grief. Arthur simply shakes his head.
Slowly, and with great care, the king takes the cloak from his shoulders. He bends down and lays it over Merlin. Both the king and Gwaine choke back a horrible noise as Arthur's hands gently pull the fabric over the younger man's face.
Mordred takes off his cloak as well and does the same.
By the time they leave the cave, Merlin held once again against Arthur's chest, the manservant had been draped with a cloak from each of them.
They begin the long, cold trek back to Camelot. They must prepare for a funeral.