At first, Merlin thinks that he's imagining things.

On Monday he steps into Gaius' workroom with his arms full of firewood, and as he turns to close the door he swears that he sees a young boy out of the corner of his eye. He whirls around to face the child, nearly dropping the wood, but there's nobody else in the room with him.

On Tuesday, he spends nearly the whole morning searching for the source of the strange dripping noise in Arthur's chambers, but discovers nothing. Arthur finds him searching under the bed as noon rolls around and startles him so much that he bangs his head on the wooden frame.

On Wednesday, every fire that he banks goes out within half an hour and he spends most of the day colder than if it were the middle of winter, even though that's a month away.

On Thursday, he's chatting to Gwen as they carry the laundry up the stairs when a man with an enormous gash across his chest walks past. But by the time Merlin realises what's he's seen and turns around in horror, there's nobody there, and Gwen is giving him a curious look as he turns back to her.

On Friday, he's mucking out the stables when the distinct smell of smoke stings his nostrils, and he looks up in surprise. Then it's burning wood and hay and manure and flesh, and he hears crackling behind him but when he looks, there's nothing. The stables are silent but for his heavy breathing.

On Saturday morning, after he's spent the entire night unable to sleep because of scratching in the walls that sounds suspiciously like rats, he decides to confer with Gaius.

***

"Have you been eating something that you shouldn't have?" is Gaius' first question, and he says it with one eyebrow disappearing into his hairline and a disapproving tone that suggests that Merlin often eats things that he shouldn't, which is a complete and utter lie and those mushrooms last month do not count.

"No, I haven't," he replies, watching as Gaius stirs a large pot of some thick, dark green liquid. "I haven't done anything, why do you always assume that?"

"Because I'm usually right," Gaius points out, and Merlin has to admit that he's right. "You say that you've been seeing people who aren't there?"

"And hearing things, and smelling things," Merlin says, and pushes himself from the table to pace around the room. "Things that I could have sworn were real. I didn't imagine the smoke in the stables, it was far too intense. And the man that I saw, he looked like he was going to die."

"But Gwen didn't see him."

"No," Merlin sighs, sitting down heavily. "Nobody did. And nobody's been hearing things or seeing things either. Have I been enchanted or something?"

Gaius gives him a long, hard look before setting down the knife that he's holding and coming to sit opposite him at the table.

"I have no doubt that if someone were to enchant you Merlin, you would be able to feel it. But I do have an idea of what might be happening – not that you'll like it. How much do you know about the festival of Samhain?" Gaius he asks, peering at him, and Merlin shrugs.

"A festival that celebrated the end of the harvest? We used to light huge fires in Ealdor, sacrificed the animals that wouldn't survive the winter. Why?"

"It's much more than that," Gaius explains, with the sort of tone that he usually employs when something's an awful lot worse than first imagined. "Samhain is also considered to be a festival of the Dead. On the night of Samhain, the boundary between the worlds of the living and the dead dissolve. The dead start to become nuisances at the eve of Samhain approaches – banging, whispering, cold spots and the like – and get more aggressive as they go. By Samhain proper, they can cause sickness, crop damage, and even death."

"So how come I've never heard of this?"

"But you have, to an extent – let me guess, in Ealdor, you would all wear masks as you danced around the fires?"

"Yes, but what's that got to do with anything?"

"People wear the masks to hide from the souls that came through from the world of the Dead meaning to do them harm, Merlin."

Merlin takes a deep breath, turning the information over in his head.

"So you're telling me that what I'm seeing are the souls of people who've died?" he asks slowly, and Gaius nods.

"I fear as much. But as to why you are the only one who can see them, I'm not sure. Samhain is old, Merlin – far older than my knowledge stretches. I have no further knowledge of the festival, and neither do my books. I'm afraid I can't help you with this," Gaius apologises, standing awkwardly as his back cracks in a few places. "But the festival will be over within a matter of days, and then all of these visions should stop."

Merlin nods and rubs at his eyes, and hopes that Gaius is right.

***

By midday on Sunday, Merlin has seen seventeen souls wandering the streets and corridor of Camelot, each one as horrifying as the next, and each

Merlin heads off towards the Dragon, the sound of dripping echoing in his ears as he leaves Arthur's chambers.

***

"Tell me about Samhain. Tell me about the festival of the Dead," Merlin says, and the Dragon holds his eye for a few moments before settling down and folding its wings in against its back.

"The eve of Samhain is the only time in the year when the boundary between worlds is thin enough that the souls of people who have died can be put to rest. It is a ritual that must be performed, and if it is not completed before Samhain's end, then the souls shall walk the earth for another year, until such time as the ritual can be performed again," the Dragon explains, for once not refusing to answer or wanting to know his purpose before even speaking. It's a refreshing change and one that Merlin's wary of, even whilst he's grateful for the quick answer.

"So these souls are of people who've died in the last four seasons?" Merlin asks, and the Dragon shakes his head slowly.

"More than that. After Uther passed the Law on magic, those with the power to perform the ritual went into hiding. There was nobody to take on the duty. The spirits have been walking these walls for twenty-one years, waiting to be sent on."

"For that long?" Merlin says incredulously, shock rippling down his spine. "Has nobody ever thought to perform the ritual at some point between Nimueh leaving and me arriving?

"Not just anybody can take on this task, young warlock. It is not enough to be able to use magic – only somebody who is magic, born of the Old Religion, can see the souls. And only the High Priest of the Old Religion can perform the ritual."

"The High Priest?" Merlin repeats, a sinking weight settling in his stomach. "Well then these spirits will never pass on because there isn't one any more. I killed Nimueh a few months ago."

"In doing so, you took on her title."

And that's enough to lock Merlin's muscles into place with a jolt, because that was something that he's never even considered before. He hasn't thought about the consequences, or who would take on the role, or if the Old Religion would even continue to exist. But then of course it would still exist – it is a part of the world, he remembers, just as the Dragon told him several months ago.

"I'm the High Priest," he says weakly, and it's much a question as a statement. The Dragon nods his great head, and Merlin swears that he almost looks pleased.

"For Albion to be born, and for Arthur to rule the land, he needs the most powerful warlock at his side. Now that you are High Priest, you will find that you can draw magic from the Old Religion much easier. Do you believe that a simple witch would have been able to nearly overthrow powerful troll magic in the same way that you did not long go?"

"You're telling me that I'm getting more powerful?"

"Every day. And it is this power that will allow you to perform the ritual on Samhain," the Dragon explains and oh, yeah, that was the reason that he came down here in the first place. Merlin shakes his head slightly, frowning.

"But how am I supposed to put them to rest?"

"That is for you to discover, Merlin. And remember – Samhain is tomorrow. You must perform the ritual before the festival ends."

As if Merlin needs the reminder.

***

Arthur knows that something is wrong, of course.

He always knows. Even if he doesn't say anything, his body does – his eyes take on a worried look, his shoulders tense, his hands reach out to touch Merlin more than usual. Sometimes he just waits for Merlin to tell him what's troubling him; sometimes he demands an explanation and won't give ground until Merlin's explaining it all to him. There doesn't seem to be a pattern for which routine he uses, Merlin realises, watching Arthur watching him as he brings him food that night. There doesn't even seem to be a pattern for when Arthur decides to believe him on most things.

"Something's bothering you," Arthur says quietly and quite suddenly, once Merlin's slumped in the chair opposite him and staring at the table under his hands. He starts and glances up at Arthur, then back down again guiltily. "Tell me what it is."

"It's nothing important. Not really," he says blithely, waving one hand, but Arthur knows when he's lying. He has done for a while.

"Tell me," he repeats, but he's not being aggressive this time, and Merlin wants to tell him. He really does but he's not sure how to, and it's not as if Arthur could help. He'd just be burdening him with things that he can't fix.

"I said it's nothing important."

Arthur just watches him for a few more moments, and then concentrates on his food. He doesn't push but Merlin knows that he's not forgotten about it, and he just hopes that he can work out how to sort this out before the end of Samhain rolls around.

There's a sudden cold blast of air in the room and Merlin nudges the temperature a little higher. Arthur glances up and presses his knee against Merlin's under the table, and Merlin ignores the dripping noise that's coming from behind him.

***

Merlin spends all of his free time reading through old texts that Gaius has dredged up, but he finds nothing of much use. The Dragon was right – this magic is far older, and far more powerful that anything he's come across before, and he's coming up with nothing.

It's just gone sundown when he traipses into Arthur's room, ready to start cleaning his armour before tomorrow's tournament. He's been training all afternoon with his men and he's collapsed on his bed fully-clothed, and Merlin undresses him carefully and helps him into bed as he drifts through a sort of waking slumber.

He's shivering ever so slightly, so Merlin walks over to the fire and light it the normal way, flint striking against stone and sparking. It takes a few minutes but a certain sense of satisfaction warms his chest when the fire grows on its own, lighting up the room, and he turns around.

And that's when he sees her, standing beside the bed, looking down at Arthur with a startling fondness.

She's beautiful – all golden hair and golden skin and bright blue eyes, and looking so full of life that Merlin thinks he might have been mistaken. But then she turns and looks up at him, and in the flickering firelight he sees the bloodstains painted down the front of her dress in cruel, mocking patterns, and she smiles.

"I have been waiting for this for a long time now," she says gently, and then all Merlin can hear is his own heart pounding and the steady dripping of her blood onto the cold stone floor.

***

Merlin would have known who she was even if she hadn't spoken but she introduces herself anyway, smiling all the time and with frequent glances over at her son. They're sat on chairs in front of the fire, talking in hushed tones even though Merlin's is the only voice that people will be able hear. Every time she looks back at Arthur, Merlin finds his eyes drawn back to the bloodstains on her white dress.

"I understand, Merlin," she says softly. "I know what it is that you're trying to do."

"I have no idea what you're talking about," he replies quickly, more out of habit than anything else, and she looks amused.

"I've known about you since you were even born," she says, tilting her head to one side as though to appraise him. "There have been stories about you for many years, about your coming. About the world that you will help my son create, and the King that you will help him become."

"Druid's tales."

"Prophecies," Ygraine corrects him, her eyes drifting back to where Arthur continues to sleep. "Nimueh told me about the future and what it would contain. She was my greatest friend."

"Nimueh?" Merlin repeats, startled, even though in the back of his mind he's always known that she played a large part in the court of the young Uther. "Are you serious?"

"You have to understand, Merlin – my husband banished her out of fear and despair. It was only after that it turned to hatred, and that she grew twisted. But without Nimueh's help, Arthur would never have been born," she explains, and a sick sort of dread creeps up through Merlin's stomach. "She gave me a son, but did not understand at the time that Arthur's life came at the price of my own. He was conceived purely of magic. Nimueh created him."

"Why are you telling me this?" Merlin snaps, looking over at Arthur himself and wanting so desperately not to believe what Ygraine is saying, even knows in his heart it makes sense. And as much as he hates Nimueh, he can't hate what she's given the world.

"Because I watched her perform the ritual that you need many times," Ygraine replies and stands, reaching for his hand. "I can help you."

He takes her hand, and it is warm in his as she leads him through the castle.

***

Gaius is just about to climb into bed when they arrive in his workshop but as soon as he sees Ygraine, he falls to his knees on the floor, a choked sound escaping his throat.

"Gaius," she says warmly, crossing over to him, and when he looks up there's a sort of desperate affection in his eyes that Merlin almost can't bear to look at.

"My Lady," Gaius whispers, ducking his head again, and Merlin can see that his shoulders are shaking. "Forgive me."

"You knew of the consequences of Nimueh's spellwork no more than she did," Ygraine points out, and moves towards the table. "Now come. Merlin has only hours to prepare for the ritual that he must perform, and he will need your help."

Merlin watches as she moves around the room with Gaius, collecting ingredients and flicking through books and instructing him on what to do, and thinks that Camelot under the reign of the young Pendragons with a sorcerer at their side must have been a beautiful place to live.

***

"I can find a way to… to keep you here," Merlin suggests awkwardly as the potion simmers between them, fumes swirling gold and white in the air, and he shrugs slightly. "I mean, so you can stay. If that's what you want me to do."

Ygraine just smiles softly and a little sadly, and shakes her head.

"I am neither in this world or the next, Merlin, and my soul is weary. It's time for me to move on. I'll see my son again when his time is due."

"He misses you, you know," Merlin says suddenly, quite without thinking, and flushes. But Ygraine's smile doesn't falter, her head tilting slightly to the side, so he carries on. "When it was birthday and he came of age, he wasn't himself. Well, he was going to be killed by your dead brother so that's kind of expected, but… I don't know. He was upset. He never met you, but he still misses you."

"I know he does," she says as though it's the most obvious thing in the world, and Merlin realises that it sort of is. "But he has you, now."

Yes, he does, Merlin thinks. But it's not the same. It never will be.

***

There's a stone in the central courtyard, Ygraine explains as they leave Gaius' workshop and the night is dark and thick around them. The stone is part of the flagging and looks entirely inconspicuous but it's a stone wrought from the Old Religion, and etched all upon it are marking that even the Dragon might not understand.

It is here that Merlin must pour the potion onto the floor and perform the ritual, in the courtyard where anybody could see him, before the sun rises. He is running out of time.

"So would it really be that much of a problem if I didn't manage to perform the ritual in time?" Merlin asks in a conversational sort of tone as they stride down the corridors, Ygraine's dress whispering around her ankles and his own hands gripping the bottle of potion tightly. "I mean, would it be so bad?"

"The longer spirits stay in the plane between worlds, the less human they become," Ygraine says sharply as they round the corner. "There are already those that have become malevolent. Think of what an evil sorcerer could do if he were to come to Camelot and find the trapped souls."

"Point taken," Merlin agrees, following her down a flight of stairs "But still, what if –"

"Merlin!"

Merlin jumps and swears, grabbing at Ygraine's arm and trying to backtrack, but it's too late – Arthur comes around the corner with a look that means Merlin's in trouble, even if he doesn't know it yet. But the expression soon vanishes as he notices Ygraine and he jumps forward even as she freezes and stares at him as though she's never quite seen him before.

"Are you okay?" Arthur asks frantically, taking her by the arm. "Are you hurt? Quick, Merlin, we need to get her to Gaius."

"She's fine, Arthur. I'm kind of busy, can this wait…?"

"What happened, my Lady?" Arthur says in one breath, ignoring Merlin completely. "Who did this to you?"

There's a moment's silence that leaves a ringing in Merlin's ears, and he watches as Ygraine's mouth curls into a twisted little half-smile, her eyes flickering across Arthur's concerned face.

"You did, Arthur," she whispers.

***

"You told me that there was nothing wrong!" Arthur snarls furiously, pacing the length of his chambers and gesturing wildly. "You said that it was nothing important!"

"And it's not!" Merlin replies, nervousness creeping up his wrists as the sky lightens shade by shade out of the window. "Look, it's not something that puts Camelot in danger, not immediately. And in a few hours it'll all be over anyway, I didn't see any need to bother you."

"I ordered you to tell me when this sort of thing happens!" Arthur reminds him, stopping his pacing to lean against the table. "You promised me that you'd stop lying to me."

"I didn't lie to you!" Merlin pleads. He crosses over to Arthur and tries to lay a hand on his shoulder but it's shrugged off, and Merlin is acutely aware of Ygraine watching them from her seat by the fire. "Please, Arthur. I need to perform this ritual before sunrise and I'm running out of time."

Arthur looks up at him with a glower and Merlin holds his breath, waiting for the tirade to continue and for Arthur to rip him apart with his words. But it doesn't come – instead, Arthur just heaves a sigh as he looks down at the table, his knuckles ivory white on the woodwork.

"And this is the ghost of my mother, is that what you're telling me?" he asks in a defeated sort of tone, and Merlin can hear the hope there too. He nods, and this time Arthur doesn't shrug away his hand.

"Yes."

Arthur takes a deep breath as he glances up at Merlin, and then a few more. Then he pushes himself up from the table and crosses to the fireplace, kneeling before Ygraine and trying not to stare at the blood painted across her dress in the shape of childbirth.

***

It's half- light as they make their way down into the empty courtyard and they move quickly, Ygraine showing him the small, square flag that will be the basis for his ritual as she keeps hold of Arthur. Merlin pours the potion onto the stone and the liquid sinks into it, glowing dull in the grooves of the sigils and markings. Merlin glances up and Ygraine nods, her hand tightening its grip on Arthur's.

It's not a particularly complex spell but it does require concentration and immense force of will, and it's a struggle not to look up at Ygraine as he recites the incantation. He can hear footsteps around himself as he speaks and a cold wind suddenly blows his hair from his face, and he knows that if he looks up that all he'll be able to see is souls.

When he finishes speaking, the liquid in the floor suddenly lights up with a blinding brightness that makes Merlin rock back on his heels and cover his eyes. It dims slightly and he looks past it, over the shining stone to where Ygraine is stood – and she is glowing just like the liquid, and just like all of the other spirits surrounding her as they light up from the inside. She's looking up at Arthur, and she's smiling.

There's a shimmer, her body jumping and shaking – and then all of a sudden she's gone, her body cast into the air in a million twinkling golden stars. They rest between Merlin and Arthur for a few seconds before fading, and the only light left in the courtyard is the torches in the distance, and the only sound is the whispering of the trees.

Arthur's hand is still clenched tightly as his side as though trying to hold onto his mother, even though she's long gone.

***

When Merlin returns from Gaius' workshop after informing his mentor that the ritual was successful, it's to find Arthur curled in a small ball in the centre of his bed, staring straight ahead at the wall. He doesn't flinch as Merlin climbs onto the bed with him and kicks off his boots, or even when Merlin lays down beside him and wraps his arms around him.

"It's okay," Merlin whispers, curling his body around Arthur's and pulling his head into his chest. "It's okay. You can let it out."

But Arthur doesn't cry.

He just allows Merlin to hold him until the first hints of sunlight show through the window, glass shattering the rays into a million pieces on the stone floor as Samhain ends and another year begins.

***

end.

***