Merlin collapses. He falls to his knees, elbows on his thighs, palms facing the cavern's roof, wherever it may be among the inky darkness.
Achlys stands before him. It is slender, broad, a human figure contained in the perfect silhouette of any human. Where its eyes should be, two gems glow amid the mist, blood-red and casting everything around it–the heavy mist and the rocks beneath–in a violent, crimson glow. The light from its eyes seems dims and with a steady, turgid rhythm. Some macabre impression of a heartbeats, manifest in the gaze of the creature.
"I am Achlys," the creature says. When it moves, it billows and glides, rising from and disappearing into the mist curling about Merlin's ankles.
It moves toward him. One arm reaches out. The fingers on its hand end in sharp talons of shadow. Merlin feels more than sees the hand.
He doesn't feel threatened.
Of all things, the gesture from the creature feels an entreaty. A plea.
"And you are Merlin," Achlys says.
"What are you, Aclys?" Merlin asks.
Achlys's eyes do not blink. The light they cast across the misty earthen floor of the cave reveals no walls or ceiling.
"I am sorrow, misery, and death," Achlys replies. "I have been your companion since birth."
Freya, Lancelot, Mordred, Arthur, Will, Balinor, Morgana–
"Why?" Merlin asks. The word is more a strangled sob than a question, but Achlys does not react to the emotion.
The creature steps forward and says, "Because it is my duty. And now I have another."
"What now?" Merlin gasps.
"Merlin," the creature says, its voice low thought it still manages to slink about the cavern before hitting Merlin's ears. "Think about it. You have been cursed with me, and I blessed with you. Around every corner, round every bend and curve your life has taken thus far, I have been waiting."
"You–"
"Me," Achlys says, voice somewhat soft. "Sorrow, misery, and death. When Freya breathed her last on the shores of Avalon, while your first and only love bled from a wound inflicted upon her by your prince, I was there," Achlys says, waving its hand. Merlin follows the gesture and sees the image of a man made of mist, cradling the form of a woman in his arms. Smoke pours from her side.
The imagine in the mist wavers, the bleeds to the imagine of a man holding another man, the one on the ground depicted with an arrow in his chest.
"When Balinor choked on his own blood in your arms, while you watched the only chance you had at a relationship with your father slip through your fingers along with his life, I watched."
Achlys continues with a swift, ruthless pace and pity and anger coloring its voice. As it speaks, the images shift between memories, painting an outline in glowing red and swirling smoke of all the memories that had been haunting the warlock's nightmares.
"When Lancelot stepped through that veil, when Morgana was dying from the poison you administered, when you were granted the vision of Mordred killing your King, when Gaius was tortured–for all of it and more, I was there."
"Why?" Merlin asks again.
His arms fold across his stomach, as if trying to hold himself together.
"Because I had to be," Achlys says, voice more patient and soft now. "Destinies are troublesome things, Merlin. And you have a troublesome destiny. Do you know what 'Emrys' means?"
Merlin sucks in a breath.
"What do you mean by this?" Merlin asks.
Achlys nods. "The druid boy told you."
"Immortal," Merlin breathes.
The word hangs in the air between them for a moment.
"Do you want to know what made all those people claw their own eyes out, Merlin?" Achlys murmurs. "What made Timothy hang himself because his wrists were opening too slowly? What made Henry beg to be cut from navel to throat in his own living room? What they saw that was too terrible to bear? "
Merlin nods stiffly.
"You," Achlys says. "I showed them you."
"My life is not that… horrible," Merlin protests.
"Look at yourself even now, Merlin," Achlys murmurs. "You will live for so long. And you really think you have seen true evil? You believe that you know the pain of sorrow, the taste of misery, and the sting of death? You know nothing yet."
"My friends have died," Merlin says, voice tight and ringing in the darkness. "I have lost parents, ture loves, best friends, all to your terror. I have seen men compelled against their morals and manipulated beyond their compassion. I have meted out death and faced it at every turn. You think I do not know you?"
"Not like you will," Achlys replies. "I wanted to know that the choice I offer is a worthwhile one. So I showed the others–Timothy and Henry and Gretel and Gabriel and Gwaine–I showed them just portions of what you will witness in your lifetime.
"And not one of them could live with it."
Merlin blinks heavily. "That isn't true."
"You know nothing of me yet, Merlin," Achlys says, and it is speaks in a regretful tone. One laced with sorrow and misery. "Would you like to see how familiar we become?"
Achlys reaches out a hand.
Merlin sees.
Arthur and the knights find the cave easily. Merlin's tracks are ragged and obvious, taking them in the exact same direction as they flee in now. The trees are too tight to allow for horses, so they plow through the thick layer of snow in as close to a dead sprint as they can manage.
None of them know how long it took them to arrive at the cave. But each came to a standstill before it, staring with sudden trepidation at the black mouth of the cave.
The longer they look, the darker the space within seems to grow. Memories come unbidden to their minds with such a ferocity and clarity that each stagger a little under the weight of them. Memories of the people they have lost, painful recollections of regrets and sorrows, wounds barely scabbed over ripped open again and left to bleed into the cold winter air.
Arthur gasps at the force with which the memories hit him.
But then, quite early on during the litany of pain and sorrow, he remembers Merlin, convulsing and choking on the floor of the Great Hall after consuming poison. Merlin, willing to do so again to save the prince from his own mistake. Merlin, sacrificing himself for the sake of Camelot and its prince–his friend–without a second thought spared for his own well-being.
Arthur stumbles forward toward the cave.
Merlin, attached by the Dorocha, half-dead next to the campfire. Merlin, caught and injured behind a rockfall. Merlin, barging into the audience hall to declare himself a sorcerer and throw himself to the blade in Gwen's stead.
The darkness of the cave swallows him and he walks onward.
Merlin, his first real friend, is in danger.
Arthur finds himself soon not at the back of a cave, but in an expanse of fog. Standing far away–too far away, too far away to reach quickly enough–is a figure made of mist and red light. It stands above the kneeling form of Merlin, whose head is bowed.
Arthur starts forward, his heart caught halfway between his throat and his chest.
And then he finds he can't move closer.
Something blocks him, keeps him hanging on the peripheral. Arthur raises a hand, runs his fingers along the invisible barrier. He curls his hand into a fist and bangs against it to no avail.
"Merlin," he calls.
"Are you ready to come home, Merlin?" the creature asks.
"Merlin," Arthur yells again, banging his fist into the barrier again.
"I am Achlys," the creature says. Its voice is almost a croon as it speaks, whispering against the stone and mist.
"Merlin!" Arthur tries again, more frantic this time.
"And you are Merlin," Achlys says.
Arthur takes his sword from its sheath and swings it in a clean and over-powered arc at the barrier. His steel bounces off it, and only his reflexes save himself from being cut on his face.
"Merlin!" Arthur cries. He tries again with his sword at a different angle, swinging it at his hip. There is no disturbance in the air, but again, his weapons rebounds harmlessly against whatever magic keeps him away from the manservant.
Frustrated tears well in the king's eyes.
"What are you?" Merlin asks.
The man's voice is small and scratchy. A pitiful thing put against its usual cheer and fortitude. Arthur winces at the sound and swings his sword again. He hacks away at the air, breath coming in staccato bursts of gasps and wordless cries.
"I am sorrow, misery, and death," Achlys responds, and Arthur's legs give out beneath him.
Hundreds of years flash before Merlin's eyes.
He sees cannonfire splitting trees into toothpicks, gouging the land and tearing men limb from limb in a burst of loud, bright violence. He sees crossbows traded for guns traded for rifles as humanity perfects machines of war. He sees the ingenuity and creativity of man craft weaponry of such power that entire countries feel the deathly shake of war in their bones.
Bombs over cities. Poisonous fogs of gas drifting over trenches. Dungeons filled with ingenious instruments of torture.
Plague upon plague, leaving millions rotting in the streets and burned from the earth away from the watchful eyes of loving family members. Entire societies erased from histories and their own dignity, displaced from their humanity. Entire peoples ground into dust, languages lost to time.
Friends made and lost to illness that eats them from the inside out, to leaders hungry for blood and power, to wars perpetrated out of paranoia and greed, to stupid, godless accidents fit for no man. Loves gained and nurtured and born, lost to the raging currents of time and violence that comprises humanity's memory.
Hundreds of years of a life, exposed to witch hunts and inquisitions and slavery and tyrrany and fear. Hundreds of years of a life bearing witness to the worst of humanity, and coming away scarred and damaged every time. Hundreds of years haunted by sorrow, misery, and death.
Achlys shows him the worst of humanity as Merlin has been destined to see it. And Merlin witnesses in horror as humanity pushes cruelty to the bounds of imagination and continues onward.
Achlys pulls away, its pulsating ruby gaze fixed on Merlin.
"This is your destiny, Merlin. This is what immortality is. This is what life is. Sorrow, misery, and death."
"Destinty is mutable," Merlin murmurs. His voice sounds like shattered glass.
"Oh, my dear boy," Achlys murmurs. "Destiny is mutable. But suffering is not."
"Why did you call me here?" Merlin asks, tears running down his cheeks.
"Long life means great suffering," Achlys says. "But it does not have to be so."
"What do you mean?" Merlin asks. He suddenly wears the expression of a starving man offered food. His gaze is hungry and searching as he looks at the creature. Desperation and sorrow cling to him like a cloak.
Achlys reaches into himself, much as a person may reach into their cloak. When it pulls its hand away, the wicked glint of steel follows it.
The blade is long, narrow, and curved. If ever there was an object to describe as lethal, this would be it. It, too, glows red in the bloody cast of the creature's eyes.
Merlin barely looks at it, instead continuing to search the creature's face.
"This is Sephtis," Achlys says.
"Eternal death," Merlin whispers.
Achlys nods. "This blade can call you home, Merlin. It is a long and painful death. But a final one."
"You mean–"
"An eternal death," Achlys confirms. "Even for one such as you."
"It can kill me," Merlin says, finally looking at the blade.
"It can call you home," Achlys corrects.
Merlin sucks in a shuddering breath. "Oblivion."
"Oblivion."
Merlin looks back to the creature, his eyes leaving the blade easily. Achlys looks back at him. The mist curls around the two, becoming thicker and more oppressive.
"In Oblivion, you will not have to witness what I have shown you. You will not even have to remember it."
"I won't?" Merlin asks. His voice is thick and slow, as if moving through honey.
"Would you like to avoid living through what I have shown you?" Achlys asks. Then, in a softer voice, more… more comforting than anything else, "Would you like to come home?"
"Please," Merlin whispers.
Achlys touches the point of the blade to Merlin's throat, just below his Adam's apple. He does not press further, does not drive the blade home.
Nonetheless, when the creature removes the wickedly sharp tip of the sword, a drop of Merlin's blood drips away from it and becomes lost in the mist at its feet.
The small nick where Sephtis touched Merlin wells with blood, then drips down his neck into his neckerchief.
When Merlin next takes a breath in, he can feel the sting of a cut growing where the cold metal had been. With another breath, he feels hot blood dripping down his neck. And with another, it coats his chest, sticking his clothes to his skin.
The stench of blood rises heavy in the air.
"Please," Merlin says again. The word becomes caught and tangled in his throat. He coughs, and watches as a spatter of black-red blood flies into the air. It dribbles down his chin, throwing steam into the air along with the mist of his breath.
"Please," Merlin repeats, and chokes again. The pain registers with him now, screaming along the growing cut on his throat. Both his hands reach up to grasp at it, as if his fingers could pull the torn flesh together and stop the bleeding.
"Please," Merlin rasps again, fighting against the warm blood filling his mouth and throat.
"Come home, Merlin," Achlys says again, and it is a prayer and an apology in one.