A/N: Do you even know how happy you make me with those little emails that tell me you put this story on alert after the first chapter? I can't begin to tell you. Here, have an e-cookie. This is so much fun to write btw! I would like to point out that this story won't really fit in a particular place in the series, and that some things won't comply with the series either (like Arthur wearing a shirt in bed, thank you Kitty O! But I needed the shirt.) So if anything bugs you beyond belief, please let me know! Otherwise, I hope it is as much fun to read as it is to write!

Merlin skids to a halt in front of Gaius's quarters, stubbing his toe - well, Arthur's toe but that doesn't make it hurt any less- roughly on an uneven slab of concrete, before bursting through the door. Gaius, who is shuffling around still dressed in his own nightgown nearly drops the bowl of porridge he is about to heat over the fire. His eyes widen when he realizes just exactly who is standing there in his room, huffing and puffing as if he has been chased by an army of wraiths, wearing a nightshift no less.

'Sire,' he begins to say not quite sure how to continue that sentence. But he doesn't have to because Merlin is already charging forward demanding to know whether-

'-Arthur is awake?'

Gaius's eyebrow snakes its way up in a manner that is all too familiar to Merlin and he realizes his mistake too late.

'I mean, Merlin. Is he in there?'

'I- well, I think so Sire. It is early yet, did he miss eh-' he glances at the prince's state of undress. 'Something?'

'Yes. No. Maybe. It isn't important. I'll just-' and with that he disappears into his own room.

The prince is sprawled all over the bed that is at least half the size of the one Merlin woke up in only moments ago. Moments that already seem like a lifetime of impossibilities. Now that Merlin is here, experiencing the sensation of looking at himself, which can't really be described as anything but disturbing, he doesn't really know what to do. So he stands there rubbing his chin for a while before realizing rubbing his chin is not something he does. Ever. So he drops the hand in a hurry and decides he can't just remain there until he turns blue. Or at least until Arthur's feet turn blue because they are becoming rather cold right now. He therefor thinks brusque action is the best route and walks over to his own window, throws it open, saying something about rising and shining. The real Arthur stirs and he groans as he turns onto his back, nearly toppling out of the small bed before telling the real Merlin in a muffled voice that really he-

'Should wash the bedding more often because it's itchy.' He stretches and yawns. 'Ugh, I feel exhausted as if I spent the day on the battlefield yesterday instead of-.' The real Arthur sits himself on the edge of the bed rubbing his eyes much in the same way as Merlin had done earlier, when he looks to the left. And to the right. And to the left again. 'Merlin,' he says with that hint of a threat as if everything is always his fault. 'Why am I in your room?'

Merlin waits for it, for the moment Arthur will turn around to face him and a detached part of his mind wonders how that arrogant little glare will look upon his own face. He straightens Arthur's shirt and Arthur's shoulders and looks as his own head starts to turn around when the real Arthur is clearly becoming annoyed at the real Merlin's uncustomary silence. The truth is, even though Merlin is still in a state of disbelief himself, when he sees the slight irritation turn into an uncomprehending frown, when Arthur jumps to his feet and his mouth opens and closes a few times, when he points at Merlin who isn't Merlin anymore but him, he has serious trouble to stop himself from laughing. Arthur says things that start with 'But,' and 'Wh-. Y-. I-' but never go anywhere, and the image is just too comical. He is watching Arthur basically go through the same motions he did earlier. The strange hands, the strange clothing, the strange feet and the dark hair. Of course Arthur wouldn't be Arthur if he didn't think throwing things would help. Merlin ducks as the pillow hurtles his way but it is closely followed by the man himself who grabs him by the shirt.

'What did you do?' he demands, attempting to shove Merlin back and forth to the rhythm of every word and only becoming more infuriated when he barely manages to make him sway.

'I didn't do anything!' Merlin tells him. 'It was like this when I woke up this morning, in eh… your bed.'

'You woke up in my bed?' he says still dragging at the shirt. 'This is madness! Impossible.' He finally lets go but his eyes keep wandering to Merlin. 'This is… utter-'. Unable to find the words, he shakes his head and rubs his eyes again, establishing that he too, is really awake. 'This is clearly magic,' he says after pacing to the opposite end of the small room and back again.

'Clearly,' Merlin snorts and immediately apologizes. 'Sorry, not the right time for being clever.'

'No. It isn't.' Arthur advances on him again but somehow Merlin finds it hard to be intimidated by - well, himself. Especially with the hair, all sticking up like that. Arthur seems to think the same thing because all he does when he reaches Merlin, is give him an odd up and down look, that starts somewhere half way his chest and ends on his nose.

'What?' Merlin demands when Arthur just keeps staring. It makes him a little nervous having his own eyes scrutinize him like that.

'Nothing.'

'What? Go on, say it!'

'I just… thought I was taller. Is all.'

'Oh no, I'm definitely taller than you are.'

'No you are not!'

'Eh, yes I am Arthur.'

Arthur opens his mouth again, then realizes the complete absurdity of the conversation and jabs a finger into Merlin's chest.

'Careful,' Merlin tells him, rubbing the spot. 'This is yourself you're hurting remember.'

'Merlin! What. Are we going to do?' Arthur demands before turning away and flopping down on the bed with his head in his hands.

'We could always ask Gaius for advice, he's just outside. Probably wondering what we're doing here.'

But Arthur shakes his head. 'No, I think we need to try and work it out for ourselves first. If my father hears of this-' he hesitates, lifts his head and looks Merlin straight in the eye. 'He'll probably execute us both.'

If there is one thing that would sober Merlin up, it is the thought of rolling heads or burning pyres so he immediately wipes the slightly amused look off his face and goes to sit beside Arthur.

'You're right. Let's think about this. What do we know?'

'It is magic, we established that, but why? Who would gain anything from swapping our-,' he cringes before saying it. 'Bodies.'

'Hmm, there doesn't seem to be any clear advantage to be gained from this. It's more like… a prank. Something a Goblin would do, or a Trickster or … something. Okay, I will go to the library and see if there are any creatures who have these kind of powers.'

'Good, but fetch me some clothes first will you. And for goodness sake, put some on yourself.'

'Eh, Arthur…' Merlin begins, trying so very hard not to enjoy what is about to follow. 'I look like you. You look like me.'

'Oh well done Merlin, catching on are you?' Arthur demands, his teeth grinding together.

'No I mean,' he clears his throat. 'I can hardly be seen serving you. Can I?'

He manages, barely, but he manages to not even allow a corner of his mouth to twitch when he watches the implications of that really sink in.