Note: the idea for this came from Bradley James and Colin Morgan saying that they thought a role swap might be a good idea when asked what other character they would like to be. Hope you like :)

Shoes On Other Feet

Arthur groaned then winced as he clapped a hand to his forehead in an attempt to stop the pounding in his brain. He didn't remember drinking an obscene amount the night before – the wine must have been a lot stronger than he thought. He blinked painfully in the light even though it wasn't all that bright and it took him several tries before he could squint narrowly enough in order to look around him. It took a little while before it occurred to him that his bed felt rather hard beneath him and – he stretched his arms experimentally – small, very small, in fact. The prince didn't remember going to someone else's bed although he supposed he wouldn't have much trouble if he'd wanted to. Arthur grinned to himself before the grin quickly faded as Gwen's image appeared in his mind. All joking aside, he would never dream of forsaking her love for a quick tumble with someone he didn't care about and any thought of her doing so sent a cold fear through his being.

So if this wasn't his bed, then whose was it? He caught a glimpse of his arms and saw that they were clothed in cloth of rather less refinement than he was used to.

"Oh, har-de-har," he said sarcastically to himself. Leon and the other knights he had been drinking with must have somehow got him drunk then dumped him in a shack somewhere.

Merlin was having the best dream where he no longer needed to scrub floors and run around after spoilt princes. Instead, it was he who was pampered and given a bed as soft as he imagined a mattress of clouds to be. He was enfolded in its deep embrace but he could feel consciousness pricking at the edges of his mind and Merlin frowned as he realised that soon he would waken and he would be thrown back into reality where his dreams of big beds and deep mattresses would remain just that – dreams.

Finally giving in to the inevitable, Merlin screwed up his nose and rubbed his eyes as he reluctantly roused himself to wakefulness.

Having no idea where he was, Arthur threw back the thin covers from what he could only laughingly call a bed and stumbled warily to the door. The sooner he got back to his own chambers and had a bath, the better!

He carefully pulled open the door and went down the few steps that led to a slightly larger chamber in which stood a familiar figure.

"Gaius?" Arthur scratched his head in puzzlement.

The older man looked back at the young man in surprise. "Merlin! What on earth are you doing here? You're late! Shouldn't you be tending to Arthur?"

Arthur stared speechless at the physician. Gaius must have finally succumbed to the doddery-ness of old age! If he didn't know better, he would have said he thought Gaius had called him Merlin.

"Merlin, didn't you hear me? Arthur will be waiting for you." Gaius began herding him out of the door as he could only continue gaping at him. "Honestly, you know better than to stay out all night at the tavern! The drink has clearly befuddled you. Now, go, else you will be scrubbing armour for the foreseeable future." Gaius gave him a final push out before closing the door on him.

Panic began to wash over Arthur as he raced to his chambers. "A mirror, I need a mirror!"

"I must still be dreaming." Merlin smiled fuzzily to himself as he lingered over the comfort of his surroundings. His eyes were closing again when he was roused by Arthur's voice shouting his name… except that it wasn't Arthur's voice… it was his own voice shouting his own name.

He sat up in his bed, now fully awake. Wait… he was definitely awake but this was not his bed but he recognised it, goodness knows he has made it and changed the sheets often enough. It was Arthur's bed!

The heavy oak door was thrown open and in burst himself looking decidedly confused and hacked off! Merlin watched himself come to a halt mid-way across the room and point at him on the bed. It took a moment for him to speak.

"Arthur! I mean, me!" The Merlin standing in the middle of the room gained a wild look in his eyes as the person on the bed let out a scoff.

"What game is this? I'm Merlin. What disguise has Gaius made?" Merlin was taken by surprise when his other self crossed the space between them and with a swift move, dragged him off the bed and over to the mirror hanging on the wall. "Wow, I'm stronger than I thought." He was impressed with himself even as he was hauled to his feet by his doppelganger.

"Arrgghhh!" The Merlin in the mirror clapped slender hands to a face that went paler than usual and was accompanied by a horrified expression.

"Oh no!" The Arthur next to him was quieter and studied his reflection with a stunned look of astonishment. "I'm you – and you're me!" He looked over at 'Merlin' who had now begun pacing up and down the chamber.

"No, no, no, no, no. NO!" 'Merlin' looked at 'Arthur'. "What manner of sorcery is this? What am I going to do? There is a tournament coming up and I can't go like this! How could this have happened?"

'Arthur' frowned and tried to think. As far as he could remember, there had been nothing unusual. He had gone home after another long day of hard work looking after Camelot's prince. As he flopped exhausted onto his bed, he recalled that he had wished that for once, Arthur Pendragon might know what it was like to be in his shoes for change. Oh, gods! That was it, his wish, but he couldn't think how it actually came to materialise though. It wasn't enough just to think something, there had to have been a spark of magic somewhere to make it come true.

"I don't know, sire." To an onlooker, it would have been the strangest sight of the Crown Prince of Camelot showing deference to his very humble manservant.

"We can't let my father know, Merlin. I don't know what he would do if he found out."

Merlin had a very good idea and it mainly involved rounding up anybody who Uther may or may not correctly guess had magic and executing them without trial in the hope that the spell on his son would be broken.

The servant had to find out how to reverse his wish before he and Arthur were found out and the king threw the kingdom into complete turmoil.

"Arthur, what are we going to do until then?"

'Merlin' stared helplessly at 'Arthur' before sighing. "I suppose we will just have to pretend to be each other until we can fix this. We will need to see Gaius, though. He has knowledge of magic, he might know how to make us ourselves again."

"My lord, I must say that I have never encountered any incidents such as the one that currently affects you and Merlin but…," Gaius continued as the faces of the two young men standing before him fell, "…that is not to say that there is nothing written about it. I'm afraid, though, that it might be a little while until I have done the necessary research."

To say that Gaius had been surprised when Merlin and Arthur had come to explain their peculiar situation to him would be a vast understatement but the physician had managed to keep his composure from slipping too much as he took in their information. Nevertheless, he was all too aware of the importance of resolving the problem away from the eyes of Uther Pendragon.

Arthur and Merlin were sat at the little table in Gaius's chambers, looking for all the world like two little boys who had just discovered that the moon was not made of cheese and there was no such thing as a gingerbread house. In short, the world that they thought they knew had just crumbled around them.

Gaius felt a wave of fatherly concern for the two men and he impulsively patted them reassuringly on their shoulders before assuming a serious expression which they responded to with a sense of alarm.

"Sire, Merlin, while you are stuck in your, um, situation, I must remind you how important it is that you behave normally. Any change in your attitudes and actions will be quickly spotted and remarked upon."

It took a moment or two for his words to sink in and if Gaius was in any doubt, it was swiftly removed by the look of outraged indignation on Merlin's – well, Arthur's – face. "You mean I will have to do his chores?" He jabbed a finger towards 'Arthur' who let a triumphant smirk cross his face at the news.

"I'm afraid so, sire," nodded Gaius.

"Ah, yes, muck the stables; scrub the floors; wash your clothes; polish your armour and boots; serve your meals, repair your weap…" Merlin counted off the tasks on Arthur's fingers.

"Stop, stop!" cried Arthur who was still in shock at this turn of events. It hadn't occurred to the prince that being in Merlin's body also meant he would have to take on Merlin's role.

"You might want to take that grin off your face, Merlin," Gaius admonished his charge.

"Eh?"

"Well, if Arthur has to do your job, then it only stands to reason that you will have to fulfil the role of Camelot's heir."

It was the turn of 'Merlin' to gain a gleeful, Arthur-like smile. "Oh, yes. Endless council meetings; tedious banquets; days away on border patrols and quests; hours and hours on the practice fields - oh and above all, being the model prince – irrefutable proof that Camelot raises its heirs to be irrefutably principled, just and noble."

Merlin's good humour faded as he realised the burden that was now on upon his shoulders. The meetings and social things, he could probably manage with a bit of luck but weapons training? That was insane, there was no way on earth that he would ever be able to handle a sword with any conviction, even if it was with Arthur's body.

It seemed to both young men that life was going to become much harder and more difficult than either had first thought.