Disclaimer: I own nothing.
Based on a random conversation with a dear friend about how boring the series would be if Merlin truly was all powerful and invincible. Kind of crack, so take nothing seriously!
All in all, Harold thought of himself as an exceptionally skilled assassin. Well, he was pretty sure that everyone he had ever gone after had never walked away alive, which in the definition of assassin, must mean that he had to be pretty good. So when he was mysteriously summoned in the middle of the night by a man in a black cloak, (and strangely, unlike most normal people, that didn't get his suspicions up, in his line of work, black cloaks were more common than normal ones,) he didn't really think anything of it. What did come as a surprise was when he found out that his employer this time was none other than a King. Apparently, Odin had grown bored and frustrated of all his previous assassins failing to kill the now King of Camelot, and had decided to hire the best.
Harold brushed it off with his usual demands for money. But inwardly, he was doing some sort of victory dance. A king had sought him out for his skills! To kill another king, someone he knew would be heavily guarded. It was every assassins dream job. You see, unlike something like a knight or a normal guard, danger for an assassin made the job more thrilling, made the rewards more beneficial. And if he succeeding in killing said King, maybe he would get a greater reward than just a bag of gold. Even assassins had hopes and dreams, right?
So whilst he managed to hide the childish excitement bubbling inside him until his mysterious black hooded guard had dumped him back outside the tavern they had found him in (assassins must be careful where they brag about their achievements, occupational hazard and all that!), Harold immediately started planning. He needed provisions to get to Camelot; maybe he should steal a horse?
In the end, Harold decided against the horse and walked to Camelot. Even if it did take him nearly three weeks. Stealing the horse would have drawn attention to himself, and it really wasn't his fault that when he asked for directions, the Druids looked at him strangely, muttered cryptic messages about not daring to harm the King and sent him in completely the wrong direction. But, because he was an efficient assassin like that, Harold didn't take the dark and ominous warnings about the unbeatable protection the king had (what assassin didn't like a challenge?) and managed to finally arrive at the gates after three weeks of wandering in the wilderness, gaining himself a new rugged look in the process.
As with any job, his first stop was the tavern. After cleaning up, Harold began to plan. The best way to kill the King was surely to take him when he was unaware, for even Harold had heard about Arthur's legendary skills with a sword. Whilst if it was any other time, he might have turned up for a tournament or two to see those said skills in action, he now thought it would be a really bad idea to get on the wrong side of said sword. Nope, Harold had a better idea than that. He was going to kill the King whilst he was sleeping. Unlike Knights, assassins had no sense of honour. Well, they did in their own way; it just didn't include honourable ways to kill someone.
So after acquiring a black cloak (and that was worryingly easy, no one found it suspicious at all! Maybe Camelot just was used to people sneaking around mysteriously?), Harold found himself sneaking into a hidden passage. Well, there was a great big feeling of secrecy about it as he crept along the dimly lit passageway, but as with the cloaks, nearly everyone seemed to know it was there.
The guards were easy to get past. All Harold had to do was toss a stone in the opposite direction and they went after it. They didn't even seem to realise that the corridor they were in was on a slope. So when the stone simply rolled down it, and then bounced noisily down a set of steps, the guards followed it. Harold nearly gave away his presence just by laughing out loud at that. It was as if they were suspecting something more was going on than just the call of gravity. Who would bewitch a stone to roll away so they could slip past the guards?
Either way, Harold wasn't going to complain. It meant that he managed to slip all the way down the corridors, and throwing another stone soon saw to the guards on Arthur's door. And then he was in. If he was honest, Harold really couldn't work out why Odin had so much trouble with killing off the King before. This was possibly one of the easiest jobs that Harold had ever done. Not that he was going to admit to it, he thought to himself as he slipped into the king's chambers and slowly began to creep towards the bed. No, he would make it out to be an epic battle in which he was almost killed before he bravely and brilliantly managed to slay the king. He was after recognition with this job.
He had made it all the way up to Arthur's bed. For someone that was supposed to be a knight and therefore a light sleeper and constantly on his guard (so Harold had been told, knights were too honourable for him to stay around for long), the King didn't stir. He looked ironically peaceful, not realising that his death was standing over him. Harold drew his dagger (actually his mother's kitchen knife, but no one need know that, it still did the job well enough) and smirked. Only someone forgot to tell poor Harold that smirks were common in Camelot, and there was one person who somehow seemed to see them all, even with the rest of the kingdom being oblivious.
"You really don't want to be doing that."
Harold leapt back from the bed, only remembering at the last minute that assassins did not scream their surprise when interrupted.
"Who are you?" He asked bluntly, hiding the dagger behind his back whilst his mind tried to come up with some excuse.
"His servant. Oh now look what you've done, you put mud over the floor! Do you know how long it took me to clean that?" The boy waved his hand at a mop and the floor seemed to begin to clean itself. Harold gaped.
"Ah..." He was beginning to realise why the others might have had had a problem. Not that it mattered, this servant was a scrawny kid. He changed the positioning of his knife, before suddenly throwing it directly at Merlin.
Only for it to stop mid-air and fall to the ground with a clatter.
"Is this your mother's?" He asked, bending down and picking it up thoughtfully. Harold made to lunge at him, but found that he couldn't move.
"Who are you?" Harold shot back, feeling his ears burn. No one had noticed the knife before until it was normally too late, and asking who the knife belonged to was not normally on his list of the top ten things to say as you are dying.
"Merlin. Although maybe Emrys would have more of an affect..?"
"Not really sure. The last assassin ran away screaming when I told him my true name. Looks like I'm going to have to try something different with you. Sorry and all that, but I really can't let you kill the prat, destiny and all that."
"You can't stop me!" Harold said, feeling quite proud of himself. So the kid had magic? He was an assassin, he would be better than that.
"Actually..." Merlin grimaced with a sigh. It was just getting too easy to stop them all. Where was the challenge these days? He never had to utter a word, and when the last few had taken one look at him and run, life was getting boring. What happened to the days where he had to actually fight to save Arthur's life? When they ran like that, he didn't even get to trade insults. And he had been working so hard on some of them.
"Can't." Harold argued, reaching for another knife concealed in his belt.
"Can. And are you looking for this?" Harold gaped. Merlin somehow already had his knife.
"All powerful warlock and all that. Sorry 'bout this." With one wave of his hand, Merlin's eyes glowed gold. Harold exploded.
Merlin sighed, looking about him as Arthur simply rolled over in his sleep.
Great. Now he had to clean the floor again.