Linger Awhile

In the beginning, it is only pain; a burning, searing, agonising pain. There is no room for anything else once the shock wears off because this new pain demands his undivided attention. It consumes him from the inside as a growling, thrashing, clawing creature that climbs from the hole in his chest and slowly, gradually, methodically tears its way to freedom.

Merlin isn't aware of much in those first few days. The moment the flames consume the little hollow boat, something inside of him snaps. Rationality and intelligence - not that you ever had much of those, that familiar voice teases in the back of his mind and makes the pain redouble - flee, and something carnal and instinctual takes over. All he knows from that span of time is pain and rage and fire.

When he finally comes back to himself, the pain dampens beneath a sudden onslaught of fear. Not for himself, but of himself, because when his sense comes back, he finds himself in the middle of a swath of destruction. Grass and brush have been burnt into the soil, even the deep roots no more than flakes of bleached ash. Rocks have cracked, shattered, decimated into thousands of tiny, piercing nails of stone. Trees - wide, ancient, sturdy pillars of time - have been cloven in two down to the bases and the taste of lightning still lingers in the gnarled splinters of wood that remain. There is nothing alive, not plant or animal, for lengths.

Panicked, dizzy with terror, Merlin stumbles in the direction of home. How far has his destruction spread? How much damage has he caused? Was anyone hurt? After all of this, after so many years of struggles, has he slipped into the darkness that had always lingered on the heels of such a great power? Has he fallen?

The appearance of green ahead nearly takes his legs out from beneath him, and once he's regained his footing, Merlin pushes on faster. He finally reaches the end - where the carnage stops as abruptly as if there were a wall to contain it - and steps into the living forest. Dropping to his knees in the damp grass, he closes his eyes and expands his senses, letting it all filter in. Life and magic, thrumming around him like a pulse, as the world spins safely on out of the reach of his massacre. Not everything is destroyed.

Behind him, a miles-wide perfect circle of annihilation. Ahead of him, the rest of the world still breathing.

Fear fades but does not vanish, and it sinks to linger with the remaining pain. Their retreat allows him to think more clearly. Arthur is gone, and although the thought sends another sharp, stabbing fire through his heart, he has accepted that. Arthur may be gone, but Camelot is not. He has a sworn duty to uphold.

Merlin uses the nearest tree to pull himself back to his feet and sets off for home.

Nowadays, it is an ache. A deep wound that is on the mend but not quite healed.

Most days he gets on just fine. He still shares the little cottage with Gaius, still studies and learns medicine and magic alike, but his days as a serving boy are over. Now he fills a position in the court, and during the royal assembly, he takes his place just behind the throne of the widowed queen.

Guinevere knows who he is - what he is. He isn't sure how, or even how long she has known, but she does. She promises him that one day Camelot will be a safe place for his people again, but that she needs his help to get there. He baulks at the idea of a council position at first - hardly fit to advise, are you, dollophead? Can't even polish my boots without mucking it up and he snarls without any real heat at the voice that still emerges from the recesses of his mind in times like this - but in the end, he can't refuse her. Even if she weren't his queen, she's still one of his best friends.

It takes time to rebuild Camelot, both physically and spiritually. The loss of their king devastates the people as much as the loss of their homes. Gwen gives them hope, as she has always done. Even more so, the child that she carries - heir to the throne of Camelot and a surprise to her as much as everyone else - brings them hope, and it is this promise of future that stirs them forward again.

As the kingdom is rising from the ashes, she makes small, gradual overtures of friendship to the Druids. Some people still resist and fear the sorcerers, but most are curious. Whispers and rumours travel, stories of the powerful warlock who brought down the sky to slay Morgana's forces, and people wonder if perhaps there is good among these men of magic.

Things are not always perfect, but they are good. Most days, he is fine.

Some days, he is not.

They come suddenly and without warning. He can get by perfectly fine for ages until some small thing happens; tiny, innocent gestures or words that serve as a stark reminder, like stretching an injured muscle too far before it's healed. Those sharp moments of pain might only last a few seconds, but they leave a dull, throbbing ache in their shadows when they go. He feels Arthur's absence like a phantom limb, a hurt with no tangible source that he can do nothing to fix.

But most days, he is fine.

Days roll into years, and now it is not only Arthur's loss that pains him.

Although it ought to have surprised no one, the death of Gaius two years after Arthur's fall still leaves many reeling, and none more so than Merlin. There had always been something immovable about the old physician; a sturdiness of spirit that gave an impression of invulnerability. Despite his advanced age, Merlin had never genuinely been able to fathom a world in which his uncle's preternaturally arched brow wasn't lifted at him in judgement.

In the end, Gaius dies quietly in his sleep. Merlin is inconsolable for weeks.

Sir Leon is the next, a few years later. An ambush during a regular patrol and the other knights can't get him back to the castle - and most importantly, to court physician and resident warlock Merlin - before the wound in his side has drained the life from him. He is far from the first knight to have fallen, but he is the first of the Round Table knights since Arthur, and the fact hits them all hard. The memorial lasts for three days.

Each new death cuts at him, picking at the scab on his heart left behind by Arthur's loss. They don't destroy him in the same way, if only because they remind him of the possibility; of the sort of horrors he is capable of creating when he lets himself.

And each time, he asks himself how many more of his friends he will have to watch die.

Although most of his pains have faded and healed with time, the agony of betrayal is one that lingers.

Whatever his intentions, Kilgharrah had intentionally kept information from him and had set him on this path. The pain of losing Arthur still cuts him, the devastation of hoping and coming so close only to lose him at the last second. It may have been some act of destiny, but Kilgharrah had known and done nothing to prepare him, and that had broken Merlin's already tenuous trust.

So despite the never-ending, keening need for answers - a need that only grows worse with each passing year - Merlin does not call on the dragon. He never figured himself for the sort to hold a grudge, but this time it feels relevant. Merlin isn't the only person who has been hurt by this. If Kilgharrah had told him, Merlin could've done something differently. Isn't it Kilgharrah who was always saying even Fate could be changed? He said nothing, Arthur died, and all that happened because of it was on the dragon.

Merlin always told himself that he would forgive the dragon one day. That he would get his answers, eventually, when the pain of betrayal was not so fresh. As had become a pattern in his life, Merlin did not consider that he could be too late.

It happens without warning. The faint pulsing has always been there, ever since Balinor's death had left him as the Dragonlord. It's distant and hovers in the background, such a natural part of him that he never consciously feels it. Unless he needs it, the presence goes completely ignored.

Until, abruptly, one day it just vanishes.

It's mid-evening, and Merlin is walking through the castle with Gwen, continuing the conversation they had been having over dinner. The faint spark in the back of his mind disappears as suddenly as a candle snuffed out by the wind, and it's absence staggers Merlin. He freezes, mid-stride, and clutches his head in surprise. Frantic, he searches through his mind - there, the constant golden hum of his magic, and there, the fragile spider-silk thread that links him to the white dragon Aithusa. But the steel chain links that once connected him to Kilgharrah are gone; broken.

Gwen is shaking his shoulder, calling his name, and Merlin comes back feeling weak and off-balanced. He brushes off her concern, reassures her he's okay despite the obvious shake in his voice, and then excuses himself. Darkness is gathering as Merlin rides out of Camelot to the large, open clearing. His voice - the harsh, guttural snarl that he's still never quite gotten used to hearing come from his mouth - breaks through the night, but without the link to connect them, the command vibrates pointlessly in the air.

Merlin spends hours shouting vainly into the shadows, but nothing ever happens. There is no buzz of acknowledgement in the back of his mind, no silhouette of wings to eradicate the stars on the horizon. It's not until the deepest part of night, when his voice has cracked and failed, that his legs buckle beneath him and he crumbles to the grass.

He doesn't know how or why, but he is certain now that Kilgharrah is gone.

Summoning his voice, Merlin calls out one last time. This time he feels it, the faintest touch against the back of his mind. It takes some time but eventually he spots the grey blur above the trees. Winds buffet him as Aithusa lands, and her talons leave shallow gouges in the earth when she steps up to his side. She still cannot speak, but he sees concern and confusion in her gaze and knows that she understands.

"It's just you and me," he says, wiping his eyes with the back of his wrist. "We're all that's left." Aithusa makes a soft crooning noise and then presses her head against his shoulder. Surprised but comforted by the contact, Merlin runs a hand along her neck and feels the webbing of scars that mar her scales.

"I'm sorry," he says, forcing back a sob when he thinks of her pain, the torment that she has been through in her short life. It's his fault, and he knows it; he is the one who brought her into this world. He forced her to hatch at a time when he was not available to take care of her, and Kilgharrah had apparently not seen fit to accept the task either. Now the Great Dragon has abandoned them both. "I'm so sorry."

Aithusa moans quietly and stretches out in the grass at his side, head in his lap and one wing draped lazily across his back; a young dragon's equivalent of an embrace. Her forgiveness - her ability to place her trust in him even when he has given her no reason to do so - is what finally breaks him.

They pass the night mourning together, and when Merlin returns to the castle at dawn it's with a promise that he will do for her what he should've done at her birth; he will raise her and teach her and protect her as a Dragonlord is supposed to do. Kilgharrah has gone, and Merlin will never have the answers he longed for, but he has been given a chance to make right on his mistake, and that will have to do.

It's only with the first hints of grey in Gwen's hair that the true, sucking dread begins to set in.

The years have flown passed, so many of them that the infant prince of Camelot is nearly a man and has started his own knight's training. Time has weighed heavily on them all, and Merlin sees it in the way that it carves lines in faces in the same way that water wears at a stone.

His appearance has never been a subject of much concern for Merlin. He is well-used to the good-natured teasing from the knights about his ears or hands or the wiriness of his frame that no amount of physical effort has changed. After he's revealed himself as Emrys, Percival jokes that Merlin's face can only be either that of a child or an old man, but that he's never quite mastered looking his age. For years, it has been only that: a joke.

Then one day, Merlin notices that there are flashes of grey amongst the curls at Gwen's temples. At first, it only surprises him. In all truth, with everything that they have been through in their lives, it feels like some small miracle that any of them have lived long enough to be affected by a thing such as age. Merlin teases her lightly about it, "no, really, it makes you look dignified, I think," and she playfully shoves him, and for a moment things are fine.

The incident, however, serves as something of an epiphany and it is like the blinders are removed from his eyes. Suddenly, Merlin realises that everyone around him is showing signs of age. Wrinkles and sun spots; a heaviness in the eyes and a certain slowing in pace and energy. Despite it all, the face that meets him in the mirror looks hardly a day older than that of the man he'd been when he'd first arrived in Camelot nearly two decades prior.

And that's when the dread - a cold and clammy fist of unrelenting terror - takes hold of his heart.

Merlin knows that his fate is tied to Arthur's, and he'd known that since his first meeting with the dragon beneath the castle. Now that Arthur is gone, Merlin is meant to stay and wait and protect Camelot until her once-and-future king returns. He had acknowledged, in a distant sort of way, that it may not happen immediately, but it is only now that he is beginning to grasp just how long it might take.

Another decade? Two? Five? Ten? Will it take generations? Will he see all of his friend's die? Will he outlive their children? Their children's children? How long will he be forced to suffer on alone in the world before Arthur returns?

After allowing himself a time to indulge in his fear and panic and self-pity, Merlin stands and faces off with the mirror again. He unleashes his magic in a rush of harsh ancient words and watches the natural furrows around his eyes deepen; the wrinkles in his brow solidify; the flecks of white blossom amid the darkness of his hairline. It isn't much, and it's a farce of magic no more real than his transformations into the old Emrys, but at the very least he no longer looks like a peer to his best friend's child.

People notice his sudden ageing, but no one says anything about it or, at the very least, not to his face. He realises belatedly that his change has only drawn attention to the fact for the few people who had not properly noticed his unnaturally slow ageing, and he is acutely aware of the whispers that dog him as he moves through the castle. Gwen gives him a sad smile, and the prince frowns - an expression of deep thought so reminiscent of his father that it's physically painful - but no one dares actually to say it.

Merlin, for his part, plays along as if nothing has changed and the others respect that decision. They go about their lives, continue building and growing Camelot into a place of strength and wonder, with the unspoken truth hanging in the air between them.

Whether he likes it or not, Merlin will outlive them all, and one day, he will be the only one left.

Even though it aches and chafes and kills him, Merlin stays in Camelot.

There are so many days when he longs to leave. Days when men younger than him fall in battle; when servants that he knew as an adolescent cave at the hands of time. He knows that each blooming sunrise brings him one day closer to the day he will lose them all. His heart aches with the knowledge, and he wants nothing more than to run.

His duty is to guard the gates of Avalon, to be waiting there when Arthur returns, but no one ever said that he must stay on at the castle. No one said that he should stay and bury the last of his friends, that he should have to watch the life leave their eyes as he did Arthur's. It would hurt less if he left now. There is no escape from the truth or the knowledge that they will go, but he does not have to watch it happen.

Still, he stays. They are the last friends that he has in the world, and he cannot bring himself to abandon them. He cannot resign himself to the loneliness that much sooner. So he stays, and he waits, and he watches them leave him one by one.

Gwen is the last, to the surprise of no one. She always has been stubborn to a fault, with the pride and strength of a queen long before she was one. After her son takes his place on the throne, she stays on to manage the castle until he takes a queen of his own. Even then, she is never absent from a council meeting. She is a terrific queen and mother and eventually grandmother.

In the end, though, even she cannot beat fate.

It is a simple illness that takes her, burrowing into her fragile immune system and refusing to let go. No matter what Merlin does, no matter how many spells or potions he tries, she fades slowly until she can no longer even get up from bed. They all know it's coming, can feel it hanging on the horizon, and they are powerless to stop it. Merlin spends any free time he can muster at her bedside, tending to her when the king is too busy.

"I'm so sorry," Merlin whispers one day as he watches over her. He had thought she was asleep, but she turns her head and frowns at him. "I've tried everything, but I just can't-"

"Merlin, no," Gwen says, and her voice is so hoarse and thin that it stabs into his heart, despite her persistent gentleness. "This is how it's meant to be. I couldn't live forever." He flinches at the same time that Gwen's face falls as she realises what she's said. She reaches out and takes his hand, threading their fingers. "I'm sorry, Merlin, that this is your fate." Because she knows, because she was the only one apart from Gaius that he ever told about his true destiny.

Merlin shakes his head, forcing back the burning in his eyes. "It's only fitting, really," he says, and he can't hide the tremor in his voice. "You were my first friend when I came to Camelot. It's only right you be my last as well." Gwen's eyes fill with tears, and he loses the battle against his own.

He is still holding her hand that night when her breathing grows shallow and weak. Gwen's family sits on her other side, the king holding her hand and stroking her hair as she struggles to keep on. The anticipation is there, and everyone knows what is coming. Her family says their goodbyes, and then Gwen turns her gaze to Merlin, and he knows that the moment has arrived.

"When you see Arthur," Merlin says, lifting her hand to press a kiss to the back of her wrist, "tell the clotpole to hurry it up, yeah?"

Queen Guinevere's last breath is a laugh, the faintest sharp exhalation, and her eyes close with the smile still on her lips.

The pain is incredible, and this time it does not fade so quickly. There is no one left but him. Every day is a reminder that he is the last and that he will never see his friends again. It hurts just to exist, and even still he stays on in Camelot when the king asks him.

He knows this boy, has known him his entire life. He raised him, tutored him, taught him everything that he could. This boy is the last living trace of his best friends, and he can't turn his back, no matter how badly it hurts. So he stays for one more generation. And, just like his parents before him, the young king of Camelot dies with Merlin by his side.

After that, though, Merlin can take no more. The day after the king's burial, the castle Warlock gathers his things and leaves Camelot for good.

The aching is a disease, and it eats away at him like madness.

He travels for a while, moving throughout Albion and doing what good he can. He tends to the sick and wounded, and heals the earth where it is damaged, and offers protection to those still outside the shield of Camelot. He upholds his duty and uses his powers for good, and for a time it helps with the pain.

But only for a time.

It occurs to Merlin, one day, that he has seen a full century of life. He has seen more years than any one man ought to, and there is no indication of an end. No escape, no reprieve, no peace.

Hopelessness drives him to recklessness. He strikes at the enemies of Camelot, one man against dozens. He tracks down any who will use magic for evil, and he deals with them. There is no challenge too great, and he runs headlong into battles alone. He is unstoppable.

Until the day when he isn't. He is blinded by rage and purpose - he has finally caught up with a ring of barbarians who deal in the slave trade, and the righteous indignation burns beneath his skin - and the arrow that strikes his side catches him by surprise. Furious, he brings down lightning from the sky and kills all in his path. It is only when the battle ends, when he stands alone in the middle of the dead, that he feels it. A cloying sickness inside of him, an intense chill that spreads out from his core and makes his blood feel like shards of ice in his veins.

He's been poisoned often enough in his life to recognise the feeling.

Only this time, Merlin isn't feeling that satisfied sense of purpose in knowing that he is laying down his life to protect something more important. There is no honour or duty in this wound. He doesn't feel justified or resigned or even scared, in the ways he's done before. He just feels - desperate. Because he's lived for far too long and seen far too much and why does Arthur get to wait it out, happy and content in Avalon, while Merlin has to slog on here every day and watch everyone he knows and loves die and it's just not bloody fair.

So when he gets back to his home - the comfortable little hovel he's set up for himself on the shores of the lake, hidden from the rest of the world by magic - he doesn't even make a motion towards his potion ingredients or spellbooks. He just lays down in his bed and closes his eyes and listens to the magic of life outside hum onward while he waits for his own to stop.

Only, it doesn't stop.

The pain is brutal, but this time Merlin refuses to do anything to get rid of it.

Without anything to stop it, the poison ravages his body. His muscles weaken, and his heart slows, and he swears that, at times, he goes days without breathing. He never moves from his bed, and he never opens his eyes. He wants it to stop, to stick, to just be real already.

Except there's something inside of him that won't let go. He can feel them warring, his two halves. Because despite it all, despite the fact that he is a creature of magic, he does still have a part of him that exists outside his magic. The magic is what powers him like the sun gives life to flowers, but there is another piece - his soul, perhaps because it is the part inside that makes him him, he thinks - that is separate.

Those two sides of him are fighting, and the battle is ruthless.

His soul is sad and battered and hopeless. It's this part, the frail blue glow at his centre, that wants to die; that cannot handle living on in this hell and just wants it all to be over; that intends to move past this pain and find Avalon, to see the people he's loved and cared for again.

The fiery gold of his magic lashes back fiercely, consumed by an overwhelming survival instinct. It's his magic that stops the poison from finishing its job, and no matter how hard his soul struggles, it isn't strong enough to fight back. His magic is stronger, something bigger than even himself, and he grapples with a truth that he's always known on an instinctive level: that while he might be able to mould and shape and direct his magic, he has no more control over it than he does the hands of time. He is merely a conduit for something greater than them all. And that something is damned determined not to let him die.

His soul fights back with everything it has; he rages, and he pleads, and he bargains. He tries tricks, letting off and trying to lure the magic into a false sense of security before sneaking under and attacking from below. (It doesn't work, of course, because the magic is just as much a part of him as his soul is, and it was a stupid, desperate plan in the first place.) He sulks and storms and strikes out, but he can find no weakness to exploit.

So he resigns himself to staying in this prison within his mind. It's not so bad here. At least in here, he doesn't have to see them, all of the people going on living perfectly normal lives and dying perfectly normal deaths. He walks the halls of his memories and relives the times when his life was good. At least then he had a purpose; something worth fighting for.

Which is, of course, when his magic decides to get nasty. (He knows that it's not entirely his magic, that it's some deep, innate part of himself that he's refusing to acknowledge, but it's easier to have an enemy, so he's going to stick with his delusions.)

While Merlin is hiding in memories of happier times, his magic stretches out its awareness. It connects with life outside of his body; to the trees and plants and animals and insects. It draws in the thrum of life, reminds him what it feels like just when he was beginning to get comfortable without it. Eventually, it extends far enough that he touches people, with their busy little lives and their fleeting emotions and their meaningful relationships, and his heart aches with longing.

More than that, though, it brings his attention to the absences. To the things that ought to be there that aren't - namely, the magic. Passing memories of the people in villages leagues away tell him stories of hardships; of battles and losses, of persecution, of plagues and darkness. He does not have the strength or focus to scrape together all of the details of what has happened, but he understands enough to see that Albion has suffered in his time away.

Damn good job protecting the kingdom, you pillock. Now you know why I never made you a knight.

And it's that guilt - the sense of his failure in upholding his duty and the question of what his mother and Gwen and Gaius and Arthur would say to see him in this state - that stops him up short. He concedes defeat, and the war between his two halves ends in an agonising, shame-faced retreat.

The pain of recovery is nearly enough to make Merlin give up all over again.

He isn't sure how much time has passed as he existed in his mental hideaway outside the constraints of the real world, but it has clearly been a greater stretch than he expected. It was only natural that his body is wasted; he hasn't eaten or drank or moved since his injury, and all this time the poison has only continued to eat away at what little strength he possessed in the first place. He anticipated the weakness.

What he hadn't accounted for was the complete inability to move so much as a particle. As he does an inventory of his body, he is horrified by what he finds. Nearly all of the muscles have disappeared from his bones, and even just the effort of his heart and lungs exhausts him. There is no strength left in him to move his limbs or even to open his eyes.

In his panic, his magic lashes out and then pulls everything inward. Merlin feels currents of life streaming into him, giving strength to his muscles and breath to his lungs. The magic pulls and pulls and pulls until he can summon up some sense of awareness. And that is when he finally begins to feel it; the life that the magic is drawing into him is coming from other things, plants and animals outside of his hovel that are withering and dying to restore his life.

Merlin immediately clamps down on the magic, cutting off the current. He can sense the absence of life around him, a complete lack of any spark of energy for nearly a mile in every direction. The realisation leaves him shaken, and he retreats inward again. He cannot die, but he will not steal the lives of others to sustain himself. There must be another way.

The first task is to rid his body of the poison. It is no easy feat, the poison so thoroughly interlaced with his blood after such a long time, and the agony is almost unbearable. He draws the poison out, drop by drop, burning its way through his skin as he forces it out like summoning water from deep within the earth. The process takes time and energy, and by the time he finishes, he feels weaker even than when he first woke, but the poison is no longer there to continually tug him closer to oblivion.

Next, he begins to rebuild his strength. His magic claws to be set free again, to gather all of the energy he could ever need into his body, but he keeps a tight leash on it. Instead, he brings the life in slowly, skimming only a little off every life force. The method is time-consuming, and forcing his awareness into ever wider circles in search of life is taxing, but he refuses to do it any other way. He has caused enough deaths already in his life, and he will not cause more when he has another option.

The first taste of water strikes him like an unexpected blow after he summons the liquid from the ground. He still cannot move, but the water droplets filter through the cracks in his lips and roll individually down his throat. His body's first instinct is to gag at the alien presence, but he doesn't have to muscles for it, so the water trails coolly into his stomach.

It takes him a considerable length of time - at least a change of the seasons, judging by the shift in wildlife he can sense in the forests around the lake - before he finally manages to open his eyes. The immediate, stabbing pain of light is agony. His magic bursts free and the glass windows of his hovel turn black. His eyes open, absorbing the darkness. There is nothing he can see, only the vaguest impressions of silhouettes in the minuscule amounts of light that bleed through the blackened glass, but for the first time in a very long time, he almost feels alive.

After that, Merlin's strength returns at an exponential rate. While those first few steps dragged on, each new ounce of strength only increases his control over his magic, and with control, he can reach further and bring more strength. In half the time it took just to be able to open his eyes, Merlin makes it to his feet.

The first glimpse of himself in the mirror is enough to horrify him for ages to come. He has been gradually lessening the dark tint of the windows, letting his eyes become slowly accustomed to the light. He catches the movement out of the corner of his eye, a brief flicker of motion, and he whirls to face it instinctively as too many years of always being on the defensive rear to the surface. The figure facing him is unrecognisable - a skeletal waif of cracked skin and wispy white hair. It looks like a corpse, like the reanimated body of a being long since dead, and that's when the truth hits him.

Merlin crumbles, what muscles his legs have recovered giving way on him, and he succumbs to grief. Because this creature that does not look like it should be alive, that looks like the possessed spirit of some dark magic, is him. This is what he has let himself become.

After that, he works harder than ever to rebuild. He doesn't look in the mirror again, the glass turned black and faced against the wall, but he focuses on regaining his strength. As soon as his eyes can handle it, he steps outside his hovel and - in the darkness of night - he hunts and gathers food. Gradually, he starts to venture out during the day as well. In the hours when he rests, when his legs are too tired to move any longer, he works on his magic. He relearns spells that have fallen to the back of his memory, stretching and flexing those just like the muscles of his body.

By the time the year's snows have come and gone, Merlin is fully alive again and ready to face the world.

It takes him some time, and many awkward conversations, to suss out exactly how long he was gone.

The answer, when he finally receives it, does not reassure him. He can't be sure of an exact number, but as they recount the stream of generations that has passed, he manages a fairly good estimate. It's been nearly five centuries since the last mention of Camelot's great sorcerer. Five hundred years. He's been dead longer than he was alive, several times over. The concept rattles him, and he immediately sets out to discover what has become of his world.

His first destination is Camelot, and he makes his way there slowly. People are kind to him - while his magic had been preoccupied with stopping the poison, it hadn't bothered with keeping his appearance young, and he hasn't felt inclined to fix it yet on waking, so he looks the part of Emrys, naturally, for the first time - and they gladly offer the charming, elderly man shelter and stories as he travels.

The world has changed so much while he's been gone, and he marvels at the technological advancements that allow them to tend larger fields and grow better crops. Voices sound differently than he remembers, dialects shifted and blurred with others to create something new. Things have changed on the surface, but the world he finds is so similar to the one he knew as a boy, apart from one thing: magic.

Magic is still there, of course, as natural a part of the world as the air and the sun, but he can feel that no one is using it. It shimmers beneath the surface like an untapped well, waiting to be drawn from. When Merlin asks people about it, they laugh and call him a silly old man full of fairy tales. "Magic isn't real," they say, "those are just old stories."

The further he journeys, the more it becomes true. He had felt the distant presence of the Sidhe and other Fair Folk at the lake of Avalon, but as he makes his way through the forest, he stretches his senses and can find no creatures of magic. He calls for Aithusa, but their connection - which had grown steadily stronger with time as he had cared for her and helped her into her power - is missing and he receives no response.

He's a Dragonlord in a world without dragons, and a sorcerer in a world without magic. He's never felt more purposeless in his life.

And although he's expecting it, has been told as much by the people he's asked, it is still a blow to his heart when he gets through the forest to find that Camelot is no more.

The castle is still there, for the most part, sections of it broken and rebuilt by years of invasion and conquest. The standard red and gold of Camelot are replaced by new, unfamiliar pennants of blue, and the people speak in a harsher dialect. The day-to-day matters are still much the same - people still tend their crops and animals, sell their wares, raise their families - but something at its core has shifted. For all that it's the same, this place is no longer Camelot. It is no longer his home.

Part of him is clamouring to lash out, to strike down these usurpers who have invaded his home. It is his duty and his destiny to protect Camelot. As he looks around, though, he doesn't see any of the anarchy or oppression he's always associated with the idea of anyone but a Pendragon on the throne. These people are happy, the hardships they face no greater than they ever had been when the kingdom was called Camelot.

Kilgharrah said that Arthur would return when Albion is in danger, and his continued absence must mean that they are in no great trouble.

So Merlin finds a place for himself in this new world, using both his natural talents and the medicinal skills taught to him by Gaius. He allies himself with no king or country, but he dedicates his life to helping the people of Albion. He has to be far more subtle about it than he used to because he can't openly use magic anymore, but he gets by, and he waits.

Without his consciously noticing it, centuries have turned into millennia.

At this point, Merlin feels he has seen it all, and yet humanity continues to surprise him. He's lived through countless wars, plagues, witch-burnings and persecutions. Each time he thinks surely this is the darkest hour, and yet humanity shows an incredible resilience. Not only do they survive, but they flourish.

People live longer lives, in sturdier homes and larger cities. The world expands beyond the shores of Albion - which is no longer called Albion - and people of fascinating new cultures bring their knowledge to the isle. Art and education swell; technology progresses. Merlin watches the advances in science with all the pride and fondness of an uncle observing the growth of a favourite nephew, always thinking of how much Gaius would love to see how far it has come from his simple experiments with plants. He learns and absorbs everything he can get his hands on; sciences, maths, languages.

In all that time, despite an intense curiosity, Merlin never leaves the borders of their isle. He doesn't stray far from the lake when he can avoid it, helping where he's able and staying out of the way when he's not. He doesn't want to risk being across an ocean when Arthur returns.

But their ever-expanding world brings with it a host of new enemies. Most fights are small and quickly dealt with, and Merlin feels confident in leaving the battles to the warriors. Then one battle explodes to encompass entire continents, voices on the radio call it a "world war," and he can sit idly by no longer.

It is simple enough to enlist - his magic covers his tracks in the new identity he created, and no one bothers to spare him a second glance. Qualified men are hard to come by, and he's got many lifetimes' experience hidden behind his faked credentials. Once again wearing the face of his youth, Merlin finds himself deployed as a medic in her majesty's army.

If there is one lesson that all his years of life have taught him, it's that for all the ways that the world changes, it will always stay very much the same. Battles are no different. Guns and tanks and planes are vicious and jarring but effective, no matter if they make him miss the elegance and grace of swordplay. On the other hand, there is something comforting about being part of a group again. The camaraderie of men relying on each other to stay alive is familiar, bringing to mind countless nights spent around a campfire in Camelot with Arthur and the knights.

These men remind him of the Knights. Not the knights of his youth, but the Round Table Knights of Arthur's rule. They come from an array of backgrounds; Charles is from a family of old money, but Liam is a baker in the shop his great-grandfather opened, and George works at the docks. Among their group are two Catholics, a Protestant, an Atheist; three Irishmen, a Welshie (which is what they refer to Merlin as because of his accent, and he hasn't the stomach to tell him he'd been around ages before Wales was a country), a Scot, and even a second-generation French immigrant. Despite their differences, they fight together as equals and friends. For the first time in a very long time, Merlin doesn't feel quite so alone.

He doesn't actively participate in the firefights much, or at least he does so as little as one can in the war-torn part of the Continent to which they're sent. It's not his job, anyhow. Merlin's role is to dodge through the trenches and keep his men alive. No real change there, come to think of it.

His magic comes out in only the direst of circumstances, in instinctive flashes of gold that deflect bullets or slow explosives. He doesn't risk it to heal; in those times he relies on science and medicine, skills he's become incredibly adept in with his millennia of practice. Even still, his men jest that they are the luckiest of bastards, escaping as many close shaves as they have, and Merlin smiles.

Then Peter takes a piece of shrapnel to his chest while Merlin is distracted with a spray of bullets on the other side. Merlin scrambles to the fallen man's side, pressing down over the injury even as blood pools up through his fingers. Peter is young, the second youngest of the group, and he has a wife and a newborn child waiting for him back in Sussex. He's choking, teeth stained in blood, and the injury is there, in the same place where an enchanted blade once took the life of his best friend, and Merlin can't stop himself.

He's stronger than he was then, by thousands, and words he doesn't recall even learning tumble off his lips. His vision flickers with gold for a moment, and then he lifts his hand and Peter's wound is superficial, his breathing even.

At the camp that evening, their small battle in the grand war finished for the time being, the men are in good spirits. They tease, exchange stories, marvel at their brilliant luck for having all escaped with their lives once again. Peter is particularly cheery, recounting to anyone who will listen that he was so sure he was dead, that it was a small miracle that his only wound had been the row of stitches on his chest.

All is well until George suddenly stumbles. The others are still laughing, mocking his lack of grace, but Merlin can feel the shift in the air. George grimaces, clutching his head. At the same time that Merlin flies to his feet, George collapses. Merlin runs to him as words from long ago come, unbidden, to his mind - a life for a life, the balance is restored.

He knows before his fingers find the spot on George's throat that the man is gone. An aneurysm is the official cause of death. A blood vessel in his brain burst. No one could have predicted it, they assure their shaken medic. He never could've known; it isn't his fault. Merlin knows better.

He never uses his magic to heal again; they lose five more before the war ends.

The world grows ever darker, and Merlin retreats from it all.

The pain of losing his men to battle is a stark reminder that Merlin is different, that he does not get the luxury of a normal life. His life is an endless stream of watching the people around him die while he suffers on, and he won't make it worse on himself by pretending. The moment they've returned from the war, he makes his way back to the shores of the Lake of Avalon and waits.

A second world war comes directly on the heels of the first, and this time Merlin doesn't join the fight. He listens and watches as the battles rage harder and fiercer and ever closer. Then there are bombs falling from the sky over London. Merlin steels himself; he won't subject himself to the pain of getting close to men who will surely die, but he can at the very least do something to protect their home.

So he does what he can, using magic to disrupt the plane's systems, but for every one plane that he leads astray, another three come in their place. There are explosions and fires and injuries and deaths. He helps where he can, heals those whose injuries are small and offers support to those who are rebuilding their lost homes, but the people are without much hope. Germans are at their gates, laying siege to the castle, and it feels like it must only be a matter of time before all is lost.

And yet they pull through. The tides of the battle shift and finally everything is safe again.

Merlin finds himself thinking, as he returns to his home at the lake, that if that was not the darkest hour to herald Arthur's return, then he does not want to see the real one. A time darker than that is unthinkable and yet, according to prophecy, on the horizon.

It happens so gradually that even Merlin - who doesn't view the passage of time on the same scale as the rest of the world - doesn't notice for a long time.

Merlin has been on his own for a few decades, ever since the end of that second global war. There have been at least a dozen more wars of varying sizes since then, battles in every corner of the world, but Merlin doesn't much bother keeping track anymore. The moment one ends another begins, and it just makes his head ache to try to follow who is fighting with whom, so he keeps to himself.

He's left alone, mercifully, despite the fact that civilisation has crept right up to his doorstep at this point. There are highways and train lines running along the shores of the lake now. He's had to take on his elderly guise again, because while the general populace finds it strange that a young man lives alone in a cottage in the wild, no one seems to be the least suspicious about a curmudgeonly old man off on his own. The young kids in the nearest town call him the Mad Hermit, and he doesn't dissuade that idea because it means no one bothers him apart from the occasional teens taunting him on dares.

Instead, Merlin focuses on honing his magic. He scours over the books he's collected, thousands of years worth of knowledge and learning pressed into brittle, yellowed pages. He learns every spell, commits each incantation to memory. There is no knowing what he may need when Arthur returns, and while he can use his magic without spells, the results are sometimes unpredictable. It's not a bad idea to prepare himself while he's got the chance.

The enchantments come easier with time. The magic requires less energy to summon, less effort to maintain. He assumes it's because he's getting stronger, like building up a muscle through exercise.

Then a Sidhe flies passed him during his evening walk around the lake, and all his assumptions fly off with it.

He was always distantly aware of the Fair Folk - a strange prickle in some back corner of his consciousness - but he hasn't been able to see one for well over a thousand years. Magic is the thread that kept their two worlds woven together, but as magic faded from this world, the Fair Folk world pulled away until even Merlin couldn't access it. He knew they were still there, living in a realm layered atop his own, but those worlds have been kept separate by the absence of magic.

Or at least they had been for a very long time.

Once he recovers from the shock, Merlin immediately sits on the shore of the lake and stretches out his awareness. He finds the magic of the world with an ease practised over millennia, but now that he's looking for it, he can feel the difference. It's less elusive, sitting closer to the surface and buzzing with possibility. This isn't the latent magic of the world lying dormant; this is magic that's alive and active.

This is the sort of magic he knew as a boy.

He can't explain how or why, but magic is coming back to the world, and he's clearly not the only one using it anymore. Magic is returning, which can only mean one thing: the time is coming.

When it finally happens, it strikes him like a physical blow, sending him bolting upright from a dead sleep. In the background, he can hear electric pops and thuds, but they are distant white noise beneath the cacophony in his head. As his awareness comes back he finds himself clutching his chest, his vision tinged bright gold. There's a vibrant warmth humming in his chest like comfort and home, and suddenly he knows, with a certainty that he can't explain: Arthur is back.

His magic is racing beneath his skin, churning and throbbing with a sudden overwhelming desire to surge forward and do. Through the gilded haze, he can see half the objects in his house are hovering, some of them bobbing idly on the air currents and others spinning like tops. The room is dark, every lightbulb shattered into dust, but as soon as he thinks it a fire roars to life in the grate.

Merlin takes a deep breath through his nose and closes his eyes, reaching out to rein his magic back under control. It's been a long time – centuries, even – since his magic has acted out like this and it takes a lot of focus before he can calm it. Even when he feels he has some measure of control again, he can still feel it charging beneath his skin like electric currents.

When he finally opens his eyes again, the gold has retreated to the edges of his vision, and most everything has fallen back to the ground. A breeze teases through the gaping windows – Merlin waves a hand, and the piles of dust on the ground solidify into panes of glass again, resuming their proper places. The electricity in the house is shot, so he conjures a dozen orbs of pale blue-white light, sending them to hover at intervals around the room.

The damage is more than he first saw; scorch marks on the walls, fragile objects smashed, holes burnt in curtains and rugs. Merlin takes a shaky breath, wanting to be horrified by the primal wave of magic throbbing through him, but all he can feel is hope. Beautiful, burning, searing, agonising hope.

Arthur is back. After all this time, so many years, decades, centuries of loneliness and pain, Arthur is finally back. He doesn't know where or how or why, but it's finally happened. The first genuine smile in over a hundred years breaks out across his face, the muscles aching at the unfamiliar contortion, and an ecstatic sob wells in his chest. Emotion washes over him and he collapses in the middle of his living room, arms wrapped around his torso like the rush of sensations might burst him from the inside.

Finally.

It takes Merlin almost four months to find Arthur, and even then it only happens by accident.

After Merlin collects himself, he rushes outside to the Lake of Avalon, but there is no one around. He paces the circumference of the lake but finds no trace of his royal prat-ness or any new magical presence apart from his own. The Fair Folk, as usual, have nothing helpful to add.

That's about the point when Merlin realises that he has no idea how this whole once-and-future-king thing works. Something in him has always expected Arthur just to come trooping out of the water, whinging about his boots being soggy. Clearly, the magic of Avalon has a different plan.

Was he reincarnated as Arthur Pendragon? Reborn into a new body; a baby that Merlin will have to watch grow until he becomes the king the world needs? Will he remember being Arthur? Remember Merlin? Or will they have to start from scratch? Will he even look like Arthur or will it be someone new entirely?

He has more questions than answers and Merlin has to stop before he panics himself into an aneurysm.

With no idea where to start, Merlin places his trust in his magic. It knew that Arthur was back, so surely it can help find him. His magic hasn't stopped humming since he first woke up and he can feel the way it is lurching and tugging, like a magnet straining to attach its polar opposite. All he needs to do is follow that feeling.

What follows is the world's longest, most tedious game of "Hot-Or-Cold."

Merlin hikes across the entire isle of Albion, chasing the faint nudge of his magic. He has melted back into the face of his youth – he woke that way the night Arthur returned without consciously doing it – and it's easy enough to play out the part of a student backpacking across the country during his gap year. He walks in one direction until the buzz of magic tells him he's starting to move away again, then changes direction slightly and keeps going.

The summer has passed and the seasons have gone cold before Merlin feels certain he's getting close. It's gone frigid in the northern country, and the first snows have already fallen in these parts, the section of Albion now called Scotland. Merlin is being powered purely by determination at this point, trudging through snowdrifts in Glasgow, then Edinburgh, then further north.

He is in St Andrews when it finally happens. Merlin had been all too happy to allow his magic to steer him toward the coast. He is endlessly fascinated by the sea. In his youth, it had been a wild, insurmountable terrain more treacherous than any other. Now, people cross it as easily as anything – he's even crossed it himself – and it's merely another road connecting them to lands unseen. Still so wild, though.

After a morning at the beach, Merlin heads back toward the city centre. Everything is geared around the university, and it's where Merlin spends most of his time, not just because he looks like he fits in there, but because there's something lively and exhilarating about the students. All of the rush and potential of people growing into their own – later than in Merlin's time, but then they live longer, safer lives now, so it balances.

The students are full of energy and excitement, so close to being set free for the holidays. Snowball fights spring up every once in awhile. Merlin feels the tingle of a young sorcerer using subtle bursts of magic to help in the battle and his heart thrills. It isn't the first time he's felt the presence of other magic-users but each time touches him as deeply, knowing they exist after so long of being alone.

Merlin's so preoccupied with the feeling that he isn't paying attention to where he's walking, and he runs straight into someone. The impact is hard enough to send them both sprawling and Merlin yelps as he tumbles into an uncoordinated heap of limbs in the courtyard. "Sorry," Merlin says on instinct, untangling himself from his scarf and turning to face the other man. He feels his heart leap up into his throat. "Arthur."

"Yeah, and you'd've known that if you'd been paying any attention to where you were walking, you ponce," Arthur snaps irritably. And it is Arthur; the blonde hair, the blue eyes, the jaw and cheekbones. Every angle and line and freckle exactly the way Merlin remembers. Everything, except the fact that his gaze glances across Merlin without the slightest flicker of recognition.

Arthur climbs back to his feet, brushing snow and slush from his jeans. Merlin scrambles to follow suit, mouth dry and feeling very much like he wants to be sick. At the same time, his magic is pulsing just beneath the surface like a second heartbeat, strong enough that he's almost afraid of losing control of it again.

Opposite him, Arthur frowns. "What are you staring at?"

"Nothing," Merlin sputters immediately and breaks his gaze. Over a thousand years and it all comes down to this. His heart is aching, like losing Arthur all over again, because this man looks like Arthur but isn't him, and that's so much worse.

Merlin's eyes land on a bit of wool, and he stoops. "Oh, you dropped your-" He offers out the knit hat, failing miserably at controlling the shaking in his voice and hoping desperately that he's doing a better job of hiding the disappointment on his face.

Arthur still looks sceptical, but he reaches out to take the hat. In the process, their fingers brush for the barest of seconds. Merlin feels his grip on his magic snap like a dry twig, and it surges through that connection like a circuit finally made whole. There is a flash of gold in Arthur's eyes, and then he doubles over with a strangled shout.

"Arthur!" yells Merlin, panicked. He crouches next to Arthur, who is clutching his head in both hands and shaking. Merlin can feel the vibrations as he grips Arthur's shoulders to stop him from collapsing fast-first on the pavement. Before Merlin can even decide what possible spell could help in the situation, Arthur's head snaps up again. The gold fades back into blue as he meets Merlin's gaze.

"Where-?" Arthur is breathing heavily, face flushed and sweat on his brow despite the temperature. He grabs Merlin's forearms with shaking hands to steady himself and glances around in confusion. Finally, his eyes return to the face only inches from his own. Arthur licks his lips. "Merlin?"

That one word nearly kills Merlin, and if it weren't for the combination of magic and adrenaline, he's sure he would've fainted into the snow then and there. Something inside of his chest clicks into place and a lifetime - multiple lifetimes - of pain wash away. "Arthur," he breathes, too terrified to hope, and yet...

Arthur's mouth quirks up on one side, an arrogant smirk that suits his face far too well, and he huffs. "We've really got to stop meeting like this."

Later, when they recount the story, Merlin will deny the string of hysterical cursing that streams out of him - (I don't even know half the languages you were speaking in). He'll deny that he went pale as a ghost - (I've always been pale!) - and he'll definitely deny the tears - (Like you're even worth it, you prat). Merlin denies the desperation behind the action when he pulls the prince into a bone-crushing hug a millennia in the making, and Arthur denies that he clings on just as tightly.

The only part they agree on, in the end, is what came next.

Merlin steps back and cuffs the Once and Future King round the head. "Took you long enough, you clotpole. And all that beauty sleep didn't even do you any favours." And then Arthur tackles the great warlock Emrys into a pile of snow.

And when all's said and done, that's the only part that matters.