This has been playing on my mind for the last few weeks, so I thought I would finally get around to writing it. Somehow it just felt like one more chapter would bring this story to a close properly.

Hope you like it.

His boots echoed loudly on the stones beneath his feet as he strode along the well-known corridors. Leon didn't need to think about where he was going. He had lived here for the majority of his life. These were the corridors he had grown up in. The same corridors he had chased Arthur around when they were just boys, the same that he had dragged the teenage prince down when Arthur refused to go to his lessons.

He didn't look where he was going any more than he thought about it. He couldn't. Looking would reveal the ghosts; the young versions of the prince laughing and sulking in turn. Right now, those memories would stop him in his tracks, would bring his barriers crashing down and for him to crumble to his knees.

This couldn't be happening.

Not now. Not after everything they had been through, everything that Arthur had become. But it didn't matter how many times Leon checked on the returning men, stragglers making it back from the battle, the king was not among them.

He told himself that Arthur would be back. After all, they had an understanding, an unspoken promise that had been part of their friendship for almost as long as Leon could remember. Arthur's place was here, in Camelot. And as his first knight – and first ever friend – it was up to Leon to make sure that was where he remained.

But when Gaius had returned alone, Leon knew that promise was shattering. Arthur was a man of his word, a man of honour. He wouldn't break that promise. Unless he had no choice. Unless it wasn't physically possible for him to return. Unless…

No.

Arthur wasn't dead. He couldn't be.

Clinging onto that thought as if it was a lifeline, Leon forced his feet to speed up again. He hadn't realised that he had been slowing as the thoughts echoed through his head. But too much time had been wasted already and he wasn't going to delay any further.

The chaos of the courtyard meant little to him. It was the same scene as the past few days. Horses and supply wagons still hadn't been stabled properly, injured men were still making their way back. It was a scene of war, a constant reminder that everyone was as numb as Leon was feeling right now. It was as if no one quite knew what to do when there was no king there to oversee proceedings.

"Someone get me a horse!" Leon called. He was known enough that none of the stable boys would dare defy him. Sure enough, it only took a few moments before a young lad appeared, leading a half-saddled horse. His face was pale and he looked exhausted. Leon took the reins.

"I'll finish it," he said gently, knowing now was not the time to make enemies. The lad nodded gratefully and hurried off, beginning to unhitch another animal from a cart and leading her into the stables. Leon found that he was transfixed by the sight. The boy couldn't have been much older than he had been when he had first arrived in the kingdom. Leon could see the same determination in him to do his part as he remembered feeling himself. His hand gently stroked the horse's neck as he sagged against the animal. He suddenly realised just how exhausted he felt.

But there wasn't time for that. Swallowing hard, he forced himself to straighten, to begin fiddling with the straps in order to leave the citadel. Just like every other time Arthur had gone missing from Camelot, Leon was preparing to ride out after him and bring him back. It had never mattered how dire the situation, it had always ended with Arthur safely back in Camelot. This wasn't going to be any different, despite his heart telling him otherwise.

He had to try.

"Where are you going?"

If Leon thought he was tired, it was nothing compared to how Gaius sounded. The old man moved slowly, looking as if he was aging decades each time Leon saw him. The knight could understand why. It wasn't just Arthur who hadn't returned, Merlin was missing as well. Although he knew they were together, Leon could see that Gaius was worried about them both.

"You know where," he said shortly, swinging himself into the saddle and preparing to move. Gaius gripped the reins, preventing him.

"You're needed here."

"There's nothing for me to do here," Leon argued. Gwaine and Percival had vanished, slipping away in the middle of the night without a word to anyone. Leon didn't need to ask. He knew they were going to find Morgana, that they had had enough. As much as it hurt, he also knew that meant there was every chance they wouldn't be coming back again. Elyan and Lancelot were dead and Gwen was not the girl he had shared his early childhood with. She was the queen now, and one trying to deal with a missing husband. She didn't need him around.

"There's plenty for you to do," Gaius said. His voice was soft and calming, but Leon could detect the stubbornness. The man wasn't going to be letting go. "The queen needs someone she can trust. The guard needs someone to give orders, they are at a loose end. The kingdom needs someone to hold it together."

"That someone is Arthur."

"Not this time."

Leon stared down at the physician. Although he knew the man was practical, he had never thought him defeatist.

"Gaius…"

"He can't come back, Leon. Not yet. If he does, he'll die."

Leon started. While he knew that Arthur was injured, he had never let himself truly think about why the king – according to Gaius – was travelling in the opposite direction to his home.

"Then he needs me to protect him."

"Not this time," Gaius echoed, and there was a fond smile in his words if not his voice. "Saxons won't harm him now. You'll never catch up with him in time."

"I can't just leave him out there alone," Leon cried, not realising that his hands were slacking on the reins as he did so. He hadn't thought about how he was supposed to find Arthur when he had no idea where the king was going. The battleground was two day's ride as it was, and Leon knew that would have to be his starting point. Arthur could literally be anywhere, and Leon was fully aware that there was more chance of him riding around aimlessly than actually being able to find Arthur in time to aid him.

"Getting yourself killed through exhaustion won't help either." There was a note of finality in Gaius' tone and Leon didn't realise the man had gestured to the stable boy again. By the time Leon looked again, the youth was standing in front of the horse, steady hands holding her halter. For a split second, Leon's hands tightened and he thought about wrenching her free and setting off.

But then he knew that Gaius was right. He had known it all along. Before he had even left his rooms, he knew his actions were ones of desperation rather than logic. But a habit of a lifetime was a hard thing to break and he looked longingly at the gate before sighing and sliding down. Gaius took his arm as the youth led the horse off, as if neither of them trusted Leon to not make a sudden dash for it. But Leon couldn't even think straight, eyes locked on the gate. It felt like he was the one breaking the promise now by giving in and staying in the citadel.

"Come," Gaius said gently, drawing him inside. Leon let it happen, knowing there was nothing he could do. He couldn't help Arthur and right now he couldn't help himself. He just let himself be steered, numbness penetrating him in a way he hadn't felt since his father's death. Before he knew it, he was sitting on his own bed and Gaius was pressing a vial into his hand, encouraging him to drink it.

Despite knowing if he did so, there would be no going after Arthur, Leon did as he was bid. The tonic washed through him instantly and the knight struggled to lift his legs onto the bed before it pulled him under.

"I… I still need…" His voice was slurring and Leon wasn't sure how he was going to finish his sentence. But he had forgotten who he was with. Gaius had been as much a part of returning Arthur to Camelot as Leon had. He knew what he was going to say.

"Arthur will know. He'll know that you wanted to come after him. But right now, he needs you here, someone to hold his kingdom together. He needs you to be as strong as you always are."

Leon's retort that Gaius was just saying that to stop him from leaving died on his lips as the potion took him under. It showed just how exhausted he was that he didn't even dream.

MMM

Arms folded, Leon leant against the turret as he stared with unseeing eyes out over the forest. Somewhere in that vast landscape was a grieving man. And – if he had understood what wasn't being said correctly – one that had the power to topple anything that stood in his way due to not thinking straight in his grief.

Not that Leon could blame Merlin. Right now, he would do anything to have a power behind him, some sort of force that would make the world understood quite how badly it had been wronged. Arthur shouldn't have died. Not him. Not Leon's golden prince, his little brat that he had spent most of his life running after. But it had. Fate had decided that there would be no returning this time and Leon was feeling the pain as sharply as a blade. He knew he should have gone after them days ago. He might have been able to help, to do something that would have ensured that Arthur lived. He could have… He could have made sure that his king knew that Leon was always going to come after him.

Only he hadn't. He hadn't gone and now Arthur had gone further than Leon could go. He couldn't bring him home from this and he had no way of showing just how unfair that was. As a knight, he had lost people before. The events of the last few years meant that he had lost men he considered to be brothers. But Arthur had always been so much more; his brother, his prince, his friend and then his king.

Letting out a yell, Leon only regretted punching the wall when he felt the blood dripping from his split knuckles. He couldn't feel it though. Physical pain couldn't touch him right now. How could it when he had broken his promise to always bring Arthur back?

Movement in the courtyard caught his eye and Leon lent forward despite himself. It seemed no matter how much he was hurting, his duty had a way of making itself known. Gaius had been right, Arthur would need him here now. He would need him to help hold together the kingdom he had fought so hard to build.

Gaius was standing alone in the courtyard, staring out in the direction of the forest. Despite being at a considerable height above him, Leon knew what expression would be on his face. It would be the same longing that Leon had felt. After all, Gaius still had someone out there he cared about, someone lost who might not be able to find his way home right now.

And that was when Leon knew.

He knew there was still a duty he could perform, not for the kingdom but for Arthur. A way of making sure he at least tried to ease the guilt in his heart about not going after the man. He couldn't bring Arthur back… But he could bring Merlin home.

The determination flooded up inside him and Leon found himself straightening before he was consciously aware of what he was doing. It helped thaw the pain and the numbness just a touch, knowing that he once again had a purpose. He had a mission he knew the king would want him to perform, and that meant nothing else mattered but that right now.

Striding from the turrets, he cursed the time it took him to reach his room again. He had never properly unpacked from the battle, convincing himself each day that he was going to ride out after his king. But it meant with just a few adjustments, he was ready to go. Sending a servant to bring supplies from the kitchen, he hurried out into the courtyard and called for a horse. Gaius didn't seem to notice him and Leon took the time to strap his pack to the saddle and check the ropes were correctly fastened. By the time he was done, the servant had arrived and helped him pack the food. Leon tipped the young man when he was done, feeling that the smile the servant shot him helped to ease the pain just a touch more.

But then he was ready and there was no time to lose. He stayed on foot as he led the horse forward, resting a hand on Gaius' shoulder. The old man looked at him, the utmost confusion in his eyes when he saw that Leon was leaving.

"I can't bring him home this time," Leon said quietly, not quite ready to say Arthur's name out loud just yet. "But he's not the only one who helped to build this kingdom. Someone isn't here who should be."

Leon watched as the hope kindled itself in the old man's eyes and he glanced towards the forest again.

"I don't think he'll want to come back. Not without his destiny by his side."

Deciding he would ponder Gaius' words while he was on the road, Leon squeezed his hand, gripping Gaius' shoulder a touch tighter.

"Then I'll take him to wherever is home for him right now. I have to do something, Gaius, and Merlin shouldn't be out there alone."

Leon knew that whatever grief he was feeling, it would be ten times worse for the king's servant. Why he thought that, he didn't know. He just knew it to be true.

"I'm not needed here right now. Gwen needs time and space. But grief makes people vulnerable and exposed. It's what…what…" he swallowed, taking a deep breath. "It's what Arthur would have wanted, I'm sure of it."

The name had felt like a stone in his throat, lodged there and threatening to stop him from breathing every time Leon tried to. The stone was still there. But now Arthur's name had crossed his lips for the first time since finding out the news, it felt just a touch smaller. Breathing - existing - hurt, but it was just a fraction easier than it had been before. Gaius turned to look at him properly, and Leon could see the man understood precisely what had just happened. Perhaps he was the only one who could understand?

"So am I," Gaius said, tears shining in his eyes. His hand came up to rest over Leon's and he returned the squeeze. "Bring him home?"

Not trusting his voice, Leon nodded. He tried and failed to force a smile and moved away. Mounting up, he touched his heels to the horse and set off towards the forest. He didn't intend to look back, not being entirely sure whether he would be returning with Merlin or not. But when the cobbled streets gave way to soil and the sky began to be obscured by the trees, he couldn't help himself. Reining the horse in, he twisted in the saddle and turned back.

The castle stood tall and proud against the sky. Despite himself, Leon smiled. This was a place he was proud to call home. He always had been, but more so in recent years. Arthur had made the entire kingdom a place Leon was proud to defend. He thought he had been under Uther, but it was only when Arthur became King did he realise what pride really meant. And it wasn't just pride in his home, but in the man Arthur had become.

Right now, it was up to him to make Arthur proud instead of the other way around. Merlin was the man's best friend, even if Arthur wouldn't admit it. Leon could see it, clearer than others because he had always known how to read Arthur's emotions. And right now, Merlin was alone and in pain. Leon had no idea if he could help or not… But he was going to try. For Arthur.

As he turned away again and nudged the horse into a steady trot, Leon realised that being on the move meant it didn't hurt so much. Although the forest was full of memories with Arthur, they were all happy ones. Moments of freedom for them both, moments of strengthening their promise of always returning home. The castle held too many unhappy memories, threatening to haunt the knight at every turn with no escape. He had been stifled and he could finally breathe again.

But as the day slowly began to pass, Leon knew it was more than that. He had been useless in the castle, too caught up in his grief to really be much help to anyone, even Gwen. But out here, he knew what he was doing and he knew how to do it. He had a purpose again, a reason to keep going.

Out here, on the hunt for Merlin, Leon knew he had one last duty to fulfil for his king. Maybe then, knowing Merlin was safe, he wouldn't be crushed by the guilt of a broken promise.

He had to try.