Hello! This is my first fanfic so I would welcome all constructive criticism and of course reviews. If you see any errors, please point them to me.

Story takes place after season 4. It's AU from that. There will be Arwen and some love for Merlin and perhaps also for the knights but no slash.

I will try to take no longer than a week to update.

I'm also looking for a beta. It would be the best if this person could also check the errors considering the content of the story but I would be gratefull if someone would check even only grammar and etc. because English isn't my first language.

Hope you will enjoy it.

I don't own Merlin.

Chapter 1

"There was this one maid in a tavern that serves the best ale in Caerleon..."

It was going to be another of his drunk stories and Arthur heard enough. "Shut it Gwaine"

"What's the matter, Princess? Jealous that you've got nothing to share? Is the Queen..."

"Choose your next words carefully" Arthur said in a deadly tone.

Gwaine's reply was lost as they walked into ambush.

Why do I always have such a bad luck? Arthur thought whilst parrying an attack. It was supposed to be only a rudimentary patrol with the Round Table. And Merlin. But that goes without saying.

Camelot's knights were outnumbered as usual, but they were amongst the best fighters in the realm and soon started pushing bandits back. Arthur dealt with his opponent and surveyed their situation. Percival was fighting three at once. Elyan had just killed one and was approaching another. Gwaine was simultaneously fighting two and winning, using his unusual fighting style to his advantage. Leon was lying on the ground, thankfully breathing and not drawing attention to himself. Arthur couldn't see Merlin, making him panic until he noticed the manservant hiding amongst the trees. As he released a breath in relief, that same breath suddenly stopped He saw Merlin's eyes turn gold.

Arthur was dumbstruck. No, no, it was impossible. Not again. Not Merlin. So caught up in his thoughts Arthur didn't notice one of the bandits sneaking behind him. He saw Merlin turn to him,eyes getting round from fear as he shouted out.

"Arthur, behind you!"

King spun and on pure instinct raised his sword, but wasn't fast enough and he got injured. Soon enough he finished the attacker off, noticing the others had already managed to drive off the ambush force. He saw Merlin running his way.

"Arthur! Are you alright?" Merlin asked, quickly spotting the king's injury. "You're hurt! Let me see," Merlin noted and without waiting for reply he started dressing Arthur's wound.

Arthur's first impulse was to snatch his arm and draw his sword, but Merlin's usual fussing stopped him. He watched him carefully and couldn't see any difference.

But there was one, wasn't there? His servant was a bloody sorcerer, after all!. No, Arthur couldn't cheat himself any longer. His only real friend was a sorcerer. His only real friend betrayed him. Because he was his only real friend and the best one too.

It was different with the knights. They were sworn by the oath, followed his orders, and these men looked up to their prince and later king.

He had to be a strong example for them constantly. With Merlin, he could just be himself. It didn't matter if he had a bad day or lost faith in himself, for Merlin was always there to encourage him and boost his confidence. If not for him, Arthur wouldn't be the king he is now. Merlin never failed to tell if he didn't agree with something his master said or done, no matter the rank.

Was all their friendship fake? It didn't seem so to Arthur. But so was with Morgana and Agravaine, and Lancelot. And even Guinevere. What was wrong with him that all those closest to him had chosen to betray him?

Merlin's betrayal hurt him much more than he was willing to admit. He was his first real friend, someone who didn't see the title but Arthur behind it and treated him the same as everybody else. Merlin was the only person he could trust. And Merlin betrayed him. It hurt much more than his now dressed wound. He'd told the knight's to head back to Camelot, and during the journey his servant as always blabbed incessantly, sometimes involved in a banter with the knights. Arthur didn't, lost in his musings.

The most often recurring question was 'why?'. Why did he start practising magic? Everyone knew that it corrupted person's soul. Then why start? Had he practised it before coming to Camelot?

If yes, then why come to the most dangerous place for a magic user? To kill him?

Even Arthur couldn't believe that. Merlin could easily poison his food. Besides that he had just saved his life in the ambush, and years ago earned his position as a manservant doing exactly the same. Arthur couldn't ignore the irony that it'd been his father himself who'd made Merlin his servant.

If not to kill, then probably to spy. As a part of a royal household he knew the value of sensitive information. His blood ran from his face when he realised just how much Merlin actually knew about Camelot and her defences. He was Arthur's personal manservant and as such went to all the Council meetings and anywhere king did. He could hand the kingdom over to anyone on a silver platter.

Arthur's thoughts became frantic when he tried to find a solution to this concerning revelation. But then he remembered that Merlin didn't know that he knew, and if he hadn't already given the needed information he may not do it for some time.

Another question was who was Merlin working for? The first thought was Morgana. He remembered that Merlin seemed to fancy her in the past, even bringing her flowers a few times. Was he just simply in love with a wrong person? No, he couldn't justify him so easily. Merlin might've had some feelings for her long ago but after their last frosty interactions he didn't think they were still there.

But if not Morgana, then who? Probably one of the kings that condoned magic. His first thought would've been Cendred. After all Merlin came from his kingdom, but the man is dead. Maybe his successor? Arthur didn't know much about Lot, but he didn't seem opposed to magic. Could it be Odin? Not likely. If it was, Merlin's role would be to kill him, not gather information. Bayard shared his father's views on magic, so not. Annis? She after all consorted with Morgana. But she was driven by grief and since then was a valued ally. Alined, Olaf, Rodor? Who knows, it could be any of them as unlikely as it seems.

And there was another question. Was Merlin working alone? Was Gaius in on it too? Because it would have been extremely hard to hide anything from the physician, and he used to practise magic too. Perhaps he was even Merlin's mentor.

What about others? Merlin was a friend with almost everyone. Servants, knights, townspeople. It could be anyone. Was Gwaine involved? They seemed to be very close, and Gwaine didn't make it a secret that he stayed in Camelot for Merlin. How could he not know? But then again, Arthur spend almost all his time with him and hadn't got a slightest clue.

Arthur sighed in desperation but straightened up in determination. He won't give up and let it break him. He will do the exact opposite. They planted a spy so close to him? Fine, he'll work it to his advantage. He will feed him false information and see who will make a move based on it. Then he will know and act. He will also closely observe Merlin. Perhaps he will gain some insight this way too. The biggest challenge would be to fool Merlin, because he knew him too well.

Chapter is now updated with corrected mistakes.