Merlin wasn't surprised to see that Arthur's first reaction upon seeing Mordred was to reach to his side, looking for a sword that no longer hung there. It was obvious he intended to attack the druid, and when he came up short on a weapon, the former king looked furious.

Mordred's lips curled into a smirk at the display, and Arthur's shoulders tensed as the blond began to stalk forward. Before a fight could break out, Merlin slipped between the two of them and held up his hands, causing Arthur to glare at him in disbelief.

"Get out of my way, Merlin."

"What are you going to do?" The warlock asked quietly, though he knew that everyone could hear every word that they said.

"I plan on stabbing him. Again."

"With what weapon?" Merlin asked, hating the betrayal that crossed his friend's face.

"Merlin—"

"Arthur, now is not the time, and you know that. Besides, you don't even have your sword, and I'm willing to bet that Mordred has some sort of magic at his disposal. He'd be an idiot to come here without it." Merlin stated, cutting his eyes to the druid who merely shrugged.

Looking back to Arthur, the warlock lifted his brows, and the former king let out a curse, turning away and running a hand through his hair before he spun around and jabbed a finger in Mordred's direction. "Is somebody going to tell me why he's even standing there?" Arthur demanded as the druid crossed his arms and scowled.

"Did you really think that you would be the only one to return?"

"Yes." Arthur and Merlin spoke at the same time, the two men exchanging a look before refocusing their attention on the young man.

"Tell him what you told us, about why you're here." Merlin gestured, only to catch the wary look that Leon sent his way.

The knight had known Arthur the longest, and Merlin was certain that he felt the tension gathering just as much as he did. All it would take was one wrong move, one wrong word, and the whole room would go up in flames before the hour was over.

"Fine," Mordred sighed, pulling apart his arms and resting one on the back of the chair he'd been sitting in. "It's about Morgana. As I'm sure you know by now, she has returned just as we have."

"We've heard." Arthur muttered, his fingers twitching at his sides.

Merlin made a mental note to find Arthur a new sword as soon as possible. Perhaps the man would not feel so restless and defenseless if he had one at his side once again.

"What she's plotting, well, it's going to be the downfall of you all."

"We'd guessed that much already, but thanks for playing." Arthur ground out, waving a hand at the druid. "Any votes on getting rid of him now?"

"Arthur." Merlin warned softly, his eyes cutting between the two as Mordred lifted his chin and glared right back at the blond.

"It's worse than you can imagine." Mordred snapped, his eyes fiery. "What I'm talking about, what she plans to do, it will be more than just your downfall. It will be the end of this very world as we know it."

"Really?" Arthur asked skeptically, his eyes narrowing at the young man whose shoulders suddenly slouched.

"She plans to ruin this world, to bring it to its very knees. She wants total control over everything, and she plans to make it her own personal playground as she sees fit."

"How would she even do that?" Lancelot cut in, his brows drawn together in concentration as Mordred stared straight at the knight.

"She's working on an Arthurian exhibit with one of the most prominent museums in the area."

"We know, we've seen the news." Merlin stated, interested himself now as the conversation veered towards a topic the druid hadn't spoken of earlier.

"Are you aware of what exactly she has in her catalog to 'display' in this exhibit?" Mordred asked, looking around at all of the knights now as well. "Any of you?"

"Why would that matter?" Arthur asked, though he caught Merlin's eye in a silent question.

"No one believes Camelot was real, your highness, that's why it matters." Mordred scoffed, turning to look back at the former king. "Which means that everything that any scholar has found in the last few centuries that might have anything to do with our past will have made it into her hands. Do you have any idea what sort of weapons she will have acquired that mortal men merely thought were stones or pointless trinkets? Magic users got by because their tools looked harmless. Goblets, stones, gems. All of which will be gathered together in one place for Morgana to use as she sees fit." Mordred spoke, his voice rising.

"You thought an army of undead were bad when they were released into your kingdom? You thought a sorceress enchanting a room full of nobles could be deadly? Imagine what she could do now, with her access to all those weapons, as well as social media."

Not a single person spoke at that thought, and Merlin felt dread growing in the pit of his stomach. When he'd first saved Arthur, so long ago it was barely a dream, it had been from a woman who had put an entire court to sleep with her song.

"You're looking at a worldwide disaster if you do not stop her before she gets started." Mordred added, looking at each of them in turn, though his gaze lingered on Merlin.

"And what about you?" The warlock asked, taking a step forward and standing only a few feet away from him.

"Yeah, how do we know that you're not helping her?" Arthur chimed in, his feet scuffling behind Merlin as he too moved closer.

"Would I really be here, outnumbered as I am, if I were?" He asked, sneering at the former king.

"Then why?" Merlin asked quietly, glaring hard at the druid. "What reason do you have to give us this information?"

"Because I.." Trailing off, Mordred glanced away with a sigh. "Because I love her."

"Gross!" Gwaine voiced from the back, only for the sound of rustling fabric and a quiet 'ow' to indicate that one of the others had hurried to shut him up.

"Not in that way!" Mordred scowled, his face beginning to turn red. "I care about her, for everything she did for me. From when I was a child, to even as an adult. I care for her like a sister. I care for her in a way that you never did." The druid stated, his tone harsh as he met Arthur's eye once again.

"I cared for her, too!" Arthur shouted, the man stepping forward as Merlin caught hold of his arm, keeping him from starting something that they would no doubt regret. "She is the one who turned her back on me, on all of us!"

"Keep telling yourself that. No one accepted her for who she was except for me. And now that we're back, she has a chance at a life again. I don't want to see her go down this path once more." A pleading expression crossed over Mordred's face, and he took a hesitant step forward. "I made a mistake back then, in Camelot. I regret my actions, Arthur. My betrayal. Your death."

"Only because it led to your death as well." Arthur snapped, trying once again to step forward as Merlin kept him back.

"Everything I did was wrong; I know that now. I know it like you wouldn't believe."

"You know, I find that very convenient."

"You don't have to believe me!" Mordred shouted, his voice cracking at the end. "I don't care if you hate me for all eternity! All I want is to save Morgana, to give her the second chance that she deserves!"

"Deserves?" Arthur scoffed, and Merlin met his eye before finally letting him go. Instead of striding forward to attack Mordred, Arthur threw up his hands and turned away. "Whatever she is doing needs to be stopped. I don't plan on risking innocent lives to try and convince her that her schemes aren't needed."

"Please. Please, help me to save her." Mordred was no longer talking to Arthur or the knights, but his pleading gaze was set on Merlin as he begged. "You can reach her; I know that you can. You two were close once, I knew it when I first saw you interact when I was a child. You can help her, Emerys, I know you can."

Merlin felt his resolve weakening as Arthur turned to glare at him. "Merlin—"

"Just let us go find peace somewhere, that's all I'm asking." Mordred spoke, lifting his hands defensively. "You'll save countless lives regardless, but this way you might help to save and change hers as well."

The warlock had to admit, the druid put up a good point. Over his many, many years of life, he'd seen too much death. The world was not black and white, the majority of people's lives were spent in the wide grey area.

He'd often wondered how different things would have been for him and Arthur if he'd entrusted Morgana with his greatest secret. If he'd helped to teach her to wield and use her magic for good, rather than evil. Would Arthur have died? Would he have managed to save Camelot?

"I cannot believe a word that is coming out of your mouth. Morgana chose her path, just like you chose yours. To ask us for help now? You're pathetic." Arthur scoffed, and Mordred scowled, gesturing around them.

"I'm pathetic? At least I'm not recreating a time when everyone idolized me! What more could you possibly want from me?"

"To swear an oath." Merlin uttered, pulling himself out of his thoughts and stepping forward to meet Mordred's stare. "Swear an oath that if you lie or betray us, that your soul will be the price that is paid."

The entire room fell silent, and Merlin could feel every eye on him. The knights had yet to see his magic, and few knew how truly powerful he could be. But as Mordred stared at him, giving the smallest nod, he knew they were all about to see his power firsthand.

The druid walked forward until they stood only inches apart, then the young man began to chant in an old, ancient language that Merlin hadn't heard from another person in centuries.

"Diegol cnytte, gewitte me yst, aliese hine. Diegol cnytte, gewitte me yst, þa tacnian me yst þonne ieceþ sicle. Gewitte me yst, þa tacnian me yst þonne ieceþ sicle. Swilte ar ond calan, drædan morðor, to cymþ."

The room dropped in temperature, the air chilling, and Merlin felt an old power rising up around them. The warlock stretched out his left hand and turned it to the side, making sure his thumb tilted up high and his palm faced his chest. Mordred mimicked the pose, and Merlin's voice joined in as the two chanted together.

"Hider eft funde. On þisse ne middangeard."

A sharp gasp left Mordred, and he backed away, his hand flying to his chest before he looked up and gave the warlock a single nod. Merlin nodded back, just before the sound of a single person clearing their throat echoed throughout the room.

"Sorry, what just happened?" Elyan asked, lifting his hand as if he were in a classroom.

"A pact has been made." Merlin uttered, his voice cold as he stared at the druid.

Their lives were bound in a way he wasn't happy about now, but it was necessary. If Mordred betrayed them, his soul would be ripped from his body. If he wasn't lying, Merlin himself would be the only one who could help him to break the pact.

The entwining of two men in such a way was rarely used, even back in Camelot's day. However now, in such a bright and new era, the warlock suddenly found himself feeling old and out of place after what had been done.

"So, will you help me?" Mordred finally asked, looking from Merlin to Arthur and back again.

"Let's see what we're dealing with first." Arthur scowled while glaring at the warlock, obviously furious that he'd now been put in the position of helping the man who was responsible for his first death.

"How are we supposed to do that?" Percival asked, folding his arms across his chest.

"We go to this new exhibit of Morgana's."

A/N

Is Mordred lying? Is Morgana going to turn good? Will everyone get the happy ending we all hoped for before Merlin ended? Probably not, but you'll have to keep reading to find out!