+

The mirror had been a gift, after a fashion; a token of the alliance between himself and Annis. Privately, Arthur wasn’t sure whether she meant it as an insult or a compliment—it certainly couldn’t be said to be in good taste.

“Think of it this way, sire,” Merlin chirped, as he helped Arthur drag the monstrosity up to his rooms. “At least something in here will be uglier than you.”

“Very funny,” It was supposed to be magic, too, though it had shown no signs of it. “That’s what I have you for.”

In the corner, the gilt edges were less obvious, and Arthur mostly forgot about the mirror until a chance encounter in the forest left his shoulder torn, his fingers slick with blood. He limped back to his chambers after the battle, a worried Merlin trailing in his wake, and his hand brushed against the glass in passing—a momentary touch that shouldn’t have changed anything.

Then: the shadow, subtle and sinister as smoke. And suddenly, everything was different.

+

“Merlin.” There were hands on his shoulder, gentle, cleaning and staunching the wound. “Do you think it tells the future?”

“What, sire?” Merlin, distracted, was frowning over his stitches, looking as unlike an evil sorcerer as it was possible to get. “The Sphinx of Astaroth? I shouldn’t think so.”

“No, you idiot. I mean the mirror.”

“Oh.” He glanced at it, and Arthur held his breath. “Doesn’t seem likely. Unless it’s showing me what happens this time tomorrow, when I have to do this all over again.”

+

The next night, it was the same ceremony. Banners on the walls, gold with a black triskelion. Merlin on his knees. This time, he saw what came afterwards: the knights in their armour, bowing before the throne, one after the other pledging their swords to him.

“Long live the king!” shouted Sir Lancelot.

“Long live the king!” shouted Sir Gwaine.

Arthur wished he could feel surprise at this defection, but they had always been more Merlin’s knights than his. Small wonder, then, that if Merlin turned from him, his men would follow. Small wonder that Arthur would fail them all.

+

And yet—Merlin seemed ordinary.

He tidied Arthur’s chambers the way he always did (very badly). He polished Arthur’s armour the way he always did (until it shone). He looked at Arthur like he was crazy when Arthur, driven to the point of desperation, asked him: “Do you ever think about being king? Of Camelot, I mean.”

“Not usually, no,” Merlin said, raising one eyebrow. “As far as I’m concerned, that’s your job, and welcome to it. Can you imagine how busy I’d be if I had to be king as well?”

So, the mirror was wrong. It had to be. Perhaps it was designed to drive men mad, to torture them with visions of what could have been. Perhaps it merely showed them the thing they most feared to see.

Regardless, he had Merlin move it to the servant’s alcove and drape a sheet over it, unwilling to be tempted into further doubt, and he told himself it was a trick, meant to torment him. The best thing he could do was put it from his mind.

+

And then, there was the magic.

+

If Arthur hadn’t been watching Merlin, he would have missed it. A branch, falling, meant little on its own, but the flash of gold in his eyes was unmistakeable.

He said nothing in the moment. The bandits were dispatched, the horses recovered, and Arthur rode hard for the citadel walls, feeling the shadow in the mirror chasing at his heels.

Inside, he dragged Merlin after him. This was a common enough occurrence that no one remarked on it; even Merlin didn’t seem inclined to challenge him, at least until they reached the annex where the mirror was stored.

“Hold out your hand,” Arthur demanded, drawing his dagger. Merlin stopped, blanched, and Arthur grabbed his wrist, drawing a bead of bright red blood from the tip of his finger.

“Arthur, what—?”

“Shut up, Merlin,” Arthur said, and pressed their joined hands against the glass.

+

They were fighting back to back in the woods; sword and magic.

They were riding at the head of an army, dressed in red and gold.

They were in the throne room of Camelot, kneeling together, Merlin’s eyes aglow as he joined their hands with a skein of golden light. As Arthur watched, Geoffrey lowered a crown onto Merlin’s head, identical to Arthur’s, and they turned towards each other in unison, reciting the hand-fasting vows with one voice.

This was the part that Arthur hadn’t seen, the part that had been hidden from him but which the addition of Merlin’s blood made abruptly clear:

The future he had seen hadn’t been his downfall.

Instead, he had been witness to their wedding.