Author's Note: I assume that this is what happened in the actual episode, there simply wasn't enough screen-time to show it *glares threateningly at the show's producers*. Therefore, I wrote it up in order to convince myself that it's real. It's not my best work, but I hope you all appreciate it!
"Is he going to be alright?" demanded Elyan, as they carefully lay the unconscious Arthur down on the ground.
"He'll be fine," answered Mordred, "he just needs to rest a bit. And someone should probably look after his wounds."
"What happened?" asked Percival.
"It was Morgana," Mordred revealed. The knights all shared quick, worried glances. "She stabbed him twice. She meant to kill him."
"It's my fault," whispered Percival painfully. His fellow knights, and even Mordred, turned to him with a mixture of stunned and confused expressions. "He gave me his sword to help free the others. I shouldn't have let him, I should have made him keep it."
"Don't blame yourself," objected Mordred, successfully attempting not to let his impatience show. "Sword or not, Arthur would never have been a match for the Lady Morgana."
"So how is it then, that you and Arthur came to be stumbling out of that cave in mostly whole pieces?" asked Elyan distrustfully. Mordred leveled him with an even gaze.
"I stabbed Morgana." A flurry of cries—some relieved, some amazed, others just plain shocked—arose in the dark caves. Mordred went on to explain everything to the knights, but Percival found that his attention was drawn by something else entirely.
Gwaine had leaned himself up against a cavern wall, and he was staring at the scene around him, his brow creased in an unusually serious expression. He alone was detached from the avid listeners of Mordred's group (some of whom were also already working to patch Arthur up as best they could). Percival picked his way through the crowd, and walked over to join his friend.
"Gwaine, you alright?" he asked. Gwaine met his eyes briefly before looking out again. Percival got the distinct impression that he was searching for something.
"I don't know," the other knight admitted, "Something feels off. I have this horrible feeling inside, but I can't place it."
"Could be just an after-shock of the battle, don't you think?" suggested Percival. "Some would consider the last few months of our lives to be rather traumatic. It's ok to feel a bit unbalanced."
Gwaine shook his head. "No, it isn't that. I know what that feels like. This is… It feels like something's missing. Something obvious. What is it, Percival?"
The bigger man shrugged helplessly. "I think you're just imagining it. We gathered up all the knights working here in the mines, and you and Arthur were the only ones who had gone missing, but you're both back now."
"Arthur…" repeated Gwaine thoughtfully. "Arthur and-"
Gwaine bolted up straight.
"Merlin!" he cried loudly. All of the knights turned to him in surprise. A few, those closest to Merlin like Elyan, Percival, and Leon, had the grace to look a bit ashamed. "Where's Merlin?"
The knights all looked at one another helplessly. No one knew where Merlin had got to.
"You!" yelled Gwaine, making his way to Mordred. "What did you say your name was?"
"Where's Merlin? Did you see him when you saved Arthur?"
Mordred hesitated, but nodded. "Morgana knocked him unconscious. I must have forgotten to tell you all in my haste to get Arthur taken care of."
"It's fine, I wouldn't expect you to remember. He's only a servant, after all. Hardly worth any consideration," returned Gwaine, sarcasm biting his tongue.
"Gwaine, calm down, he didn't-"
"I'm going to look for him," Gwaine interrupted smoothly. "I'll be back soon."
Gwaine grabbed a torch and strode away from the knights, back in the direction of the cave that Arthur and Merlin had found him in earlier that night.
As soon as he stepped into the entrance to the cave, he began to call Merlin's name out loudly. No one answered. Gwaine hurried his pace, not caring to be cautious at all as he continued shouting for his friend.
"I'm here!" finally came an echo-y reply. Gwaine's heart jumped with relief and he picked up the pace again so that he was practically jogging through the tunnels in the direction of Merlin's voice. Turning one last corner, he stopped.
There Merlin was. It looked as if Merlin was already struggling to rise from where he lay on the ground, propped up against the rough stone. Gwaine grinned and rushed over, reaching down. The two men clasped forearms and Gwaine pulled Merlin abruptly to his feet, causing him to wince a bit.
"Thanks," said Arthur's servant.
"No problem," returned Gwaine, still grinning. "You had me worried, you know. Not to mention, you left me alone with all the other knights. I was starting to worry I was the only sane one left."
"Oh yeah. Always."
Merlin stepped forward and stumbled a bit, but Gwaine's arm was around him a flash, holding him upright. Together they made their way towards the cave's exit.
"Are you alright, Merlin?" he asked more seriously, the concern clear on his face.
"Yeah, I'm fine. But Arthur, is he-"
"He's fine," Gwaine assured with a gentle smile, "The knights are taking care of him." He paused. "Merlin, I'm sorry it took me so long to find you. Everything was so chaotic, and I just had this feeling of forgetting something… And then I finally realized that it was you. I should have realized sooner, I'm sorry."
"No, it's fine, really," said Merlin, smiling gratefully at the knight.
"That boy Mordred should have told us about you right off, and I would have been in here looking for you several minutes ago, but it managed to slip his mind in his haste to protect Arthur."
"Well, he's right. Arthur's protection is priority-"
"Merlin," Gwaine interrupted firmly, "Your life is just as important as Arthur's. Do you understand me?"
Merlin was surprised by the fervor in Gwaine's voice, but he smiled appreciatively, actually a bit overwhelmed by the thought of someone caring that much about him. He couldn't even begin to describe how good it made him feel.
"Don't forget, Merlin," the knight continued, "You're still the closest friend I have. I'm not going to lose you."
After spending so much time in Arthur's company, who was only recently improving at addressing his feelings and was still not this forthright with them, Merlin was left speechless. He was truly touched by Gwaine's declaration, as he'd honestly assumed that after becoming a knight of Camelot and bonding with the other knights, Gwaine had ceased to hold Merlin in such high esteem. Apparently he's assumed incorrectly. Merlin had never been happier to be wrong.
"You sure you don't just want me around because I'm willing to put up with you when you're completely drunk?" he teased. Gwaine laughed merrily.
"Ah, alright, you caught me!"
Gwaine and Merlin continued their friendly banter all the way out of the caves. As they continued on, they began to hear the sounds of the knights echoing from the turn ahead. Merlin stopped Gwaine with a hand on his arm. Gwaine raised his eyebrows, but turned to Merlin expectantly.
"Thank you, Gwaine," said Merlin softly, "for finding me. And just for looking at all. You're a great friend."
"You deserve no less," Gwaine answered sincerely. The two men shared a smile, and continued forward to rejoin the other knights.