Set after season 3. And Arthur isn't such an ass and knows when he is wrong. Check the song 'Sacred Worlds' by Blind Guardian, it's where I got the inspiration for this story.
Arthur, Merlin and the Knights of the Round Table where in the forest outside of Camelot on a hunting trip. It was the second day of the trip and they still haven't caught anything, mostly because of Merlin. But nobody really didn't mind, they were out in the forest so that they can get away from the city for a while. They were out to relax, the actual hunt was secondary.
Arthur and Merlin were at the front bantering, as usual, while the knights were behind them and absent mindedly looking around for some game while they talked.
But suddenly bandits attacked them, taking them by surprise. There were quite a lot of them, at least four bandits against one knight.
"Merlin, stay behind me!" shouted Arthur before he engaged in battle. Even with Arthurs protection, some bandits got through his defense and started to attack Merlin.
As soon as he saw the bandits that went after him, Merlin took a sword from a bandit that lay there dead. He tried defending himself, but it was apparent that the enemy had more training then him, which wasn't that hard. And that he has to start to use magic if he wants to survive. One bandit, with an axe, swung at Merlin, but he dogged it. And as it got stuck in the tree, he used magic to make the branch that was above the bandit fall on him. It knocked out some of the other bandits that were near him.
As Merlin looked around to see where the others were, he saw that they were all scattered. Arthur was furthest from him, and he was fending of three bandits. But to his horror he also saw a fourth one coming up behind him, sword raised, and Arthur was too distracted to notice. Merlin looked around to see if one of the knights is near enough to help the prince. They were all fighting too far away from Arthur to get there in time to save him. Merlin has only one choice if he wants his prince to survive, magic.
He lifted his hand in Arthur's direction and started chanting. His eyes started glowing gold as practically half of the tree besides Arthur broke and fell on the bandit behind him.
When Arthur heard the noise he lifted his head, and the first thing he saw was Merlin with an arm raised in his direction. Even from the distance, he could see that Merlin's eyes changed color. When he turned his head around, he saw a bandit under the tree that has just fallen.
He finished off the three bandits that were in front of him as soon as he could, and went off to help his knights. He will talk to Merlin when they are done.
Even though they were outnumbered, the knights and prince were able to defeat the enemy quickly.
After cleaning his sword and putting it back in its scabbard, Arthur grabbed Merlin by the arm to hold him in one place if in case Merlin wanted to bolt.
"What did you do back there with the tree? And don't you dare lye to me." Said Arthur, his eyes piercing Merlin's. But Merlin just looked down and mumbled something.
"What did you say? I didn't understand you." Said Arthur. The commotion between them has drawn the attention of the knights and they moved a little closer to listen in.
Merlin took a deep breath and lifted his head to look his best friend, the Prince of Camelot, in the eyes, and said with a quiet voice (the knights had to strain their ears to hear anything): "I used magic, sire."
The first thing that Arthur felt was shock. He couldn't believe it. His manservant, his best friend, has lied to him all these years and didn't tell him that he had magic. After the shock he felt betrayal. He thought that there were no secrets between Merlin and him. He has shared his secrets with Merlin that he didn't dare tell anyone, and Merlin has shared some of his own, but it seems Merlin didn't trust him enough to tell him this one until the moment where he had no more choice.
He let Merlin's arm go as if he was burnt and turned to his knights. "We will start looking for a place for the night. It will be dark soon." With that, he turned his back to Merlin and walked away. The knights hesitated a bit but then also followed him. Lancelot stayed behind and put a hand on Merlin's shoulder, who looked like he would start crying any moment.
"Everything will be alright, you'll see. Just give him some time to think about this." Said Lancelot and followed the others after Merlin nodded.
It was late at night, the knights were all asleep, Merlin was taking watch duty and Arthur was somewhere in the woods searching for more firewood.
Merlin was so engrossed in his thoughts, (where either Arthur kills him because of his magic or doesn't care and is still his friend (he likes the later thoughts much better))that he didn't notice the person that he was thinking about dump the firewood that he has found and sit right beside him. Merlin was confused to say the least.
Arthur was staring intently at the fire and for some minutes was completely ignoring Merlin. But then he took a deep breath and, still looking at the fire, said:"I've been raised my whole life thinking that magic was evil and that it corrupted everyone who possessed it. And it was confirmed every time when we were attacked by sorcerers these few years, and when Morgana left as well. But I just can't think of you in any evil concur-the-world way." Arthur chuckled a bit emptily." But who could ever imagine that the clumsy and always smiling idiot could be a sorcerer. And I have to ask: are you the exception, the only good one among the many evil sorcerers, or do I have such luck that I only meet the ones who want me dead?"
Merlin looked at the prince from the corner of his eye, he has also noticed that the knights have awakened and are listening in. He took a deep breath as well, to slow down his heart beat a little and answered truthfully:" You do have the bad luck to only meet the ones out for your head, but there are good sorcerers as well. I want you to know that magic isn't evil, it's just a weapon, like your sword. And I want you to know that I never used my magic against Camelot or you, I only used it to help."
"Tell me about all those times where I was an idiot and you used magic right under my nose." Said Arthur as he turned to Merlin and gave him a small smile.
Merlin grinned from ear to ear. Arthur knew about his magic and he wasn't dead! There was a small (big) celebration in his head. He told Arthur and the knights, who stopped pretending that they were asleep, about all those times that he used his magic since he came to Camelot to save their sorry asses (in not so many words), he even told them that he is the last Dragon Lord. When he was finished Arthur was holding his head with one hand as if it was spinning."That is a lot to take in." muttered Gwaine, the others just nodded.
Then Arthur shot his head up, looked at Merlin and said:" You can't come with us to Camelot." That startled Merlin and the rest quite a bit.
" What? Why?" asked Merlin.
"You said it yourself, you were almost caught numerous times. I can't have you die because you used magic to help us. You should leave now and return when I'm king, then you can use your magic freely." He answered.
Merlin was stunned, but he had to admit that Arthur was right. It was pure luck that he wasn't caught by now. But what really stunned him was what Arthur last said 'when I'm king, you can use your magic freely'.
"If that is the case, then Merlin should leave now." Said Leon. At the looks of the others he just shrugged and said:"Merlin should get a head start. He was constantly in danger in Camelot, the sooner he leaves the sooner he is in safety."
"Then it is decided. Let's pack some things for Merlin that he will need." Arthur said. He got up and started to pack some provisions into Merlin's backpack. The knights nodded and got up to do the same.
Merlin got up to protest, but before he could say a word an arm wound around his shoulders. He looked to his left to see that it was Gwaine who did it.
"Merlin, you should know by now that your protests won't bring anything. You are our friend, you have been with us all through thick and thin. And even though the Princess over there won't admit it, you are his friend too. So shut up for once and let us help you." Said, for once, a somber Gwaine.
When they were all done, they were escorting Merlin to the edge of the forest. When they got there, everybody said their goodbye. When it was time for Arthur to say his goodbyes to Merlin, they stood in front of each other a bit awkwardly. But then Arthur released a frustrated groan and just hugged Merlin.
"Make sure you come back alive, that's an order." Arthur said when he released Merlin.
Merlin rolled his eyes."Yes, sire."
"And when you come back, you are going to be my Court Sorcerer."
"You can't be serious." Merlin said wide eyed.
"I'm very serious Merlin. If you have managed to survive this long, then I'm sure that you will be able to be my Court Sorcerer." Arthur said with a big and satisfied smile on his face. Merlin was at a loss of words, so he just nodded. When he looked everyone one last time in the eyes, he turned around to leave.
"Oh, and Merlin!" Arthur shouted.
Merlin turned around."Yes, sire?"
"If I need a servant in another life-"
"Don't ask me, you dollop head." Merlin answered, then turned around and left.
It has been a few years since Merlin left, and Arthur was King. He has lifted the ban on magic and a few sorcerers have joined him, among them was Mordred. He was disappointed when Merlin didn't show up. He didn't know why that clumsy idiot didn't show up and he didn't want to think about it, it only brought terrible thoughts that Merlin was, maybe, dead.
Right now, Camelot was under siege. Morgouse and Morgana are attacking Camelot with magic and an army, on two fronts. Mordred was doing all he could with the other sorcerers they had, to fight the two sisters with magic, but Morgana and Morgouse had more sorcerers.
The Knights of Camelot and the Knights of the Round Table were doing all they can to defend the citadel. The lower town was already taken.
It seems to Arthur that Camelot would be, for the first time, taken.
When a fire ball has passed him and destroyed the wall right behind him, Arthur shouted for his men to retreat further into the citadel.
"Retreat!" he shouted. But before his men could do that, there was another explosion and some more of his men died.
The Knights of the Round Table got around him, he understood their message. If they were going to die, they might as well do it together. Only one member of their group was missing, and all of them hoped that at least he would survive.
Just when it looked like everything was over, there was a mighty roar coming from the sky. Everyone could feel it in their bones. Then there was a big golden dragon coming towards them, Arthur recognized him as the dragon that attacked Camelot so many years ago. He didn't know if it was on their side or the enemy's. But he didn't have to worry for long as it started to blow fire at the enemy.
The sorcerers didn't have enough time to put up shields as they were the first ones who were attacked. With them gone, Mordred was able to help the Knights of Camelot with the enemy's army. The battle was now in their favor. The dragon was shooting fire at the soldiers, but Arthur could make out a figure that was on the dragons back.
"Attack!" Arthur shouted. With the dragon on their side, the moral of the soldiers went sky high and they attacked with new vigor. Now they had a chance to defeat Morgouse and Morgana.
The dragon gave another mighty roar and lunged for the hill right in front of Camelot. The dragon started to shoot fire, and then Arthur saw that light started to shoot out of the figure on the dragon. The hill almost exploded when dose combined powers hit the hill. Arthur could hear two women screaming, it seems that the dragon and its rider went right for the source.
After that, it wasn't hard to defeat the soldiers that were left. After the battle was over, the dragon landed in a clearing right outside of Camelot. Arthur and the Knights of the Round Table went to it as fast as they could. When they got there, the dragon just looked at them and then flew of. The figure that was on it standing and looking at the dragon as it flew away, his back turned to the others.
When the man, it was obvious that it was a man, finally turned around, there was no mistaking of who it was. The black hair, white skin, high cheekbones and big ears told you everything. It was Merlin. His clumsy manservant has returned and has just saved the day.
Merlin grinned from ear to ear."Hello, sire."
"You incompetent little idiot." Said Arthur as he embraced his best friend for the first time in many years.
Said idiot just grinned wider into his shoulder."I'm coming home." Arthur squeezed him tighter as the knights joined in to make a group hug. His friend was finally home.