Day 1
The problem, Arthur realised as he shuffled around trying to get comfortable on a pallet so skinny his shoulder blades popped over the edge on each side, the problem was that he had stood in the Throne Room and insisted to this father that he was going to swap with Merlin for a week and there was nothing he could do about it.
He could hardly turn around now and say, oh sorry I was tricked and I've changed my mind. It's possible that some people might declare him stubborn but Arthur was mentally insistent to himself. He'd made this... really really small and uncomfortable... bed and he was bloody well going to lie in it. Every night for a week.
"Damn you, Merlin," he cursed his servant even as he watched the sun slowly rise over Camelot through the small window in his room. Oh damn, breakfast!
Arthur (Merlin! he reminded himself, today I'm Merlin) leapt out of bed, suddenly realising that he was supposed to bring Merlin (Arthur, he's Arthur) his breakfast an hour after sunrise and that was sooner than he'd realised.
He pulled a shirt on over his one pair of trousers (he'd already searched the room in the hope of finding some of Merlin's clothes hidden but they seemed to have been secreted elsewhere) and stumbled down the stairs to the living area.
"Merlin," said Gaius cheerfully. He was sitting at the table eating what looked like porridge. "Are you only just getting out of bed? I thought you'd gone to get the mushrooms."
"Mushrooms?" asked Arthur, confused, "what mushrooms?"
"The mushrooms I needed for the formulation I'm doing today. Well, you'd better go and get them quickly, otherwise I won't be able to get Uther's potion to him by tonight. They have to be picked before the sun is fully risen."
"But, breakfast..." Arthur tried to argue.
"You should have gotten up earlier if you wanted something to eat. You don't have enough time now, not if you intend to deliver Arthur's breakfast within the next hour. Or do you want me telling the King his potion is not ready because you did not get the ingredients?"
Gaius handed him a bucket and a spade and directed him gently toward the door.
"Now hurry back with those and then take the Prince his breakfast. Oh, and remember that it's Thursday. Be back by mid morning so we can go pot collecting."
"But, Merlin, I mean, Arthur, is going on patrol two hours after breakfast. He needs his horses tended to."
"Then you should have done that last night before you went to bed. Honestly, Merlin, who said you could sit around all evening doing nothing? Now get to it, we've both got a busy day."
And he was so tired from lack of sleep and so flustered that he didn't see the amusement on Gaius' face as he left the room. If he had, he might have questioned whether Gauis would really threaten to accuse Merlin of incompetence to the King or send him out without breakfast.
But he didn't see it and so he strode blithely off into the forest to the spot Gaius had indicated and then looked down in horror at the seven different types of mushrooms growing there. He had no idea which type Gaius wanted; he'd just have to pick them all.
"I'm going to need a bigger bucket."
"Honestly, Merlin, what do you do all day?" said Arthur as Merlin struggled in with his breakfast tray a full two hours after sunrise. Arthur (Merlin! he thought, I'm Merlin) wondered just how long his former servant had been standing there waiting to deliver that line and suspected it had been all morning.
He placed the tray down, looked up at the raven-haired man before him and did a small unnoticeable double take. Because somehow and from somewhere Merlin had gotten appropriate attire for a Prince and he looked, well, princely. Someone had also tackled his terrible hair cut and had arranged it so his ears were not so prominent. His deep blue doublet made his eyes look even bluer and disguised the angularity of his form.
"Gods," exclaimed Arthur (Merlin!), "you could actually pass for a Prince."
"And you could definitely pass for an incompetent idiot of a servant," grinned Merlin and Arthur couldn't help but grin back.
"The problem is that some arrogant ass didn't bother to tell me about the mushrooms I was supposed to collect this morning," he said sardonically.
"Oh, the mushrooms. Sorry, as the Crown Prince I have no knowledge of mushrooms. I guess that must be one of the many extra things you do that I don't notice because I'm such a conceited, self-absorbed git."
"You know, you could have found a more subtle way to make your point, Arthur, but as dense as I am I can understand something if you state it outright, something you might have to work on."
"Princes don't do subtle."
"Yes, as I said, you've made your point so can we swap back now?"
"You're not actually trying to back down from our deal, are you? After less than one day? What would people say? Come on, being me isn't that hard. After all, I manage to do it every day."
"Fine," said Arthur, who was just starting to work out what a mess he'd gotten himself into and had decided to face it with resigned fortitude. "So I suppose I should make your bed and clean your chambers while you eat breakfast and go on patrol with the Knights?" The Knights, he thought, oh this could be fun. Let's see how he feels after a morning with the Knights. He'll be begging me to swap back.
"I also need you to launder my robes for the Midwinter Festival tomorrow night. Oh, and Merlin, remember to launder yours as well."
"Yes my Lord," said Arthur (Merlin! he thought, I'm bloody Merlin), even as the words stuck in his throat. "Will there be anything else while you're gone?" The words came out of his mouth but what he was thinking was: I hope you fall off your horse and Sir Leon laughs at you.
"Oh yes, Merlin, of course. Tomorrow night, make sure you wear the hat." And he waltzed out the door with a giant, undignified unPrince-like grin on his face.
"That devious, scheming, underhanded...skinny, big-eared, funny-faced..." the insults continued (and continued getting lamer) echoing off the walls as he cleaned his own chambers hoping against hope he could finish by mid morning so he could go pot collecting (what the hell was pot collecting anyway?), and all the time cursing a certain dark-haired servant who'd obviously been planning this little revenge for a while.
"I'll show him," he muttered to himself as he plumped the pillows and changed the sheets. "I'll show him how easy it is being him. You just watch. I'll show him."