A/N: So, this bunny got into my head a while ago, and I've just now managed to type it up. I'm actually really excited about where this is heading.

Story starts between Seasons 2 and 3 for Merlin (Morgana is still missing and Uther is still king), and during the Golden Age for Narnia (almost exactly ten years after the Kings and Queens defeat the White Witch). This worked out really well, because everyone is around the same age.

Arthur, Peter, and Morgana: 23
Susan: 22
Merlin: 21
Lucy: 18

Pairings undecided. No slash, no incest. Rated T for violence in later chapters and language.

Disclaimer: I do not own Narnia or Merlin. Narnia belongs to C.S. Lewis. Merlin belongs to BBC.

P.S. This chapter is un-Beta'd, so please forgive any mistakes - and please point them out so that I can fix them! If anyone would like to Beta Once and Future, please PM me! Thanks!

Once and Future, Chapter One: Camelot
In which a Myth is introduced, a Knife is found, and a Prince is a prat.

"Merlin, what are you doing?" The young manservant jumped nearly a foot in the air, almost knocking a full inkwell onto the map he had been reading.

"Nothing," he said automatically, knowing that he looked quite guilty, though he hadn't really done anything wrong. Well, not this time, at least. When his brain caught up with his body, he realized that his actions were purely instinctual - he had been caught in so many compromising positions, where he actually had been doing something he shouldn't have, that he now associated Arthur's unanticipated arrival with panic and spur-of-the-moment cover stories. The epiphany made him blush - was it really as bad as that?
Remembering that Arthur was waiting for a valid answer, Merlin amended, "Uh, just looking at some maps. I never realized that there were other countries beyond the Eastern Mountains."

"Well, what did you think was there?" the prince asked, coming to stand beside his manservant.

"I dunno, the ocean?" Merlin looked at the map again. "Why haven't I heard of any of these? That one looks enormous!" He pointed to a particularly large area on the map.

"Narnia," Arthur nodded. "It's wild, from the stories. Legend has it the country is ruled by an evil sorceress who keeps the land under a constant blanket of snow. Has been that way for over a century. The Northern region of Camelot used to get freak snowstorms coming through the mountains, even in the middle of summer here. I barely remember them, though. I was only a boy when they stopped coming." Merlin remembered hearing stories that were much the same. Ealdor, too, had been hit with harsh blizzards coming from over the mountains, though to his knowledge they hadn't plagued the border village for at least a decade. He remembered whispered warnings of sorcery - he'd always had his ears open to such rumors - but no one had pointed a finger his way, so he hadn't given the cause of the blizzards much thought. He'd been too concerned with trying to survive.

"So you've never been there?" Merlin asked, suddenly curious about the countries beyond the mountains.

"Of course I have," Arthur exclaimed, "because when I hear about a sorceress who can enchant an entire country for a hundred years, my first instinct is to go exploring! What do you think, Merlin?"

"Point taken," the warlock muttered, backing off. Even to him - curious, open-to-magic Merlin - the prospect was a little frightening. He knew he was powerful, but that? Arthur had the right idea; keeping his distance seemed to be the preferable option.

"The only country we can even think of contacting on that side of the mountain range is Calormen-" here the prince pointed to a country to the south of Narnia, "but it isn't regular. In order to get there, we have to go through Mercia - it's the only area where the mountains are relatively passable. And Lord Bayard isn't exactly open to discussing trade routes with Camelot." Merlin understood this; the ruler of Mercia still felt slighted from his visit three years before. While it really wasn't Uther's fault - the cup had been poisoned - Bayard certainly didn't see things that way. "Not that we are missing much," Arthur continued, "From what I hear, the people of Calormen are cruel and treacherous." Arthur resumed his inspection of the maps, hardly giving the Eastern countries another thought.

"What about that one?" Merlin asked, pointing once again to a country East of the Mountains. "Archenland?" Arthur shrugged.

"No news comes from there. By now, it might not even exist. This map is almost as old as my father, and not very reliable besides. It seems unlikely that a country that size could retain its independence for long, especially flanked by two countries as big as Narnia and Calormen."

Merlin found it strange that he had never heard of Narnia. From the looks of the map, it wasn't exactly a small place. Even with the mountains, there should have been at least some news. The warlock resolved to ask Gaius about it the next chance he got.

The "next chance" didn't happen until hours later, when Merlin was sitting down to dinner. They were preparing for a journey North to confirm threats of Cenred's troops crossing the border, so Arthur'd had him running all around the castle to get ready. Such missions were always dangerous - especially since Arthur could only take a select few of his knights with him. A scouting party had to be small, or it would defeat the purpose.
So the thought of enchanted countries had been completely driven form Merlin's mind in favor of more relevant issues - such as clean armor and polished boots. But now the day was winding down, and Merlin finally had time to wonder again.

"Gaius, what do you know about Narnia?" the boy asked, inhaling delicious stew for which Gaius was renowned. The physician in question froze, his own spoon halfway between the bowl and his mouth.

"Why do you ask?"

"Saw a map today in Arthur's chambers," the boy said offhandedly. "Arthur didn't know much, except that it was supposedly ruled by a sorceress powerful enough to cover the entire country in snow for a century." Merlin had expected there to be some falsehood to the claim. He knew how stories and rumors could get embellished over time and distance. Besides, he was the most powerful sorcerer ever born in Albion, and he knew that he didn't have the ability to keep a whole country enchanted for one year, much less a hundred.

"The rumors are true, as far as I know," the old man said, to Merlin's dismay. "And there is evidence."

"Yeah, Arthur said that Camelot used to get snow in the middle of summer," Merlin said around a mouthful of liquid. "Ealdor did, too."

"I don't expect that either of you would remember much of them," Gaius said, "but the storms were an absolute nightmare for the people of Camelot. No one was able to predict their coming. They would appear without any kind of warning, destroy homes and fields, then disappear just as quickly. When Uther - and Cenred and Bayard as well, I think - sent scouts to investigate, they didn't return. Occasionally a horse would appear, rider-less, wondering around the Northern plains, but more often than not they disappeared with the scouts. Eventually, the kings ceased their exploring, unwilling to waste any more lives than necessary."

"Arthur said the country was wild." Gaius nodded.

"According to early accounts, Narnia was primarily inhabited by what we would call creatures of myth. Talking Beasts and tree spirits and even creatures with the bodies of animals, but the heads of men. And that the land was protected by a Great Lion who lived beyond the Eastern Sea. Even before the Winter began, strange tales came from Narnia. And that was all that came from the country. No men were ever reported to come in or out of the Lands of the East." Gaius paused for a moment, as if deciding whether or not he should continue. Eventually, he said, "Merlin, do you remember me telling you that magic is a part of Albion, woven into the very fabric of its existence? Well according to legend, Narnia was - is - a country even more dependent on magic. Apparently, magic there is as natural as gravity." Merlin tried to imagine the place Gaius was describing, but it sounded like a land of fairytales. The young warlock really couldn't picture a land where Winter always reigned and magic was the norm.

"But all you have is legend? There are no confirmations?"

"There are a few stories that make their way from Calormen, oh, every ten years or so, but I don't think they are very reliable. Last I heard - and this was years before you came to Camelot - a few children had come and killed the Sorceress, and were ruling in her place. But that is perhaps the most absurd thing I've ever heard." Merlin agreed, but his curiosity was far from sated. He lay thinking late into the night, and when he finally fell asleep he dreamed of fur coats, an evil Witch, and a very powerful Lion whose breath calmed him and rid him of any other dreams.

The next morning saw a busy Merlin with no time to think of magical lands or living trees. He was actually rushing around Arthur's chambers, looking for the Prince's favorite knife. He thought he had put it in its usual place - on the table beside Arthur's bed, within reach should the sleeping Prince need it - but was dismayed to find it missing.

"Merlin, you do realize that I could have been attacked last night," Arthur was saying, "and that I would have been defenseless."

"Yes, but you weren't," Merlin retorted. Anyway, he thought, I doubt a knife would prove much use against anyone who managed to bypass my wards. Of course, he couldn't say this out loud, though he dearly wished to. He had long ago decided to put protective spells around the Prince's chambers to keep away any unwanted visitors during the night. So far they had… relocated two would-be assassins and three sulking chambermaids. Merlin wasn't entirely sure where the assassins had ended up (he had made sure that the maids were returned to their homes) but he knew it was some place unpleasant. Arthur's voice brought the warlock out of his reverie.

"But I could have been," the Prince insisted. "And my knife wouldn't have been there, and I could've died. And it would have been your fault."

"I happen to know that you sleep with a knife under your pillow, and another under the mattress. And your sword stays at the food of your bed. And if you were attacked, you would have used the one under your pillow, which is much longer and a little sturdier."

"How did you know about the one under the mattress?" Arthur asked, shocked.

"I've cleaned every inch of this room more times than I can count. I know all of your little hiding places. I know where you keep the plans for the Citadel, all the treaties you've practiced drawing up - and that letter to Lady Vivian you told me you'd destroyed." Arthur paled. Actually, Merlin hadn't been sure about the letter, though he had suspected. He made a mental note to look for that hiding place the next time he was in the room alone. "Aha!" He held up the lost knife triumphantly.

"About time." Arthur snatched the weapon from his grinning servant and all but stomped out of the room. "Merlin, ready my horse. I expect we'll be riding out within the hour. I want to be ready by that time." Merlin stuck out his tongue, rolling his eyes at his master's receding back.

The small group - consisting of only Arthur, Sir Leon, Sir Geraint, and, of course, Merlin himself - was indeed ready in under an hour, and had set off as soon as possible. It would take roughly three days to get to the border (not far from Ealdor, to Merlin's delight), and another three to get back. Arthur always set aside a full day for the actual scouting period - sometimes longer, but this was an area that the group knew well, so they weren't expecting to take more than that - which meant that they shouldn't be gone for more than a week. It wasn't meant to be very dangerous, though Merlin was now convinced that a freak blizzard would sneak up on them and trap them. Still, the company wasn't overly somber upon their departure. Even Merlin - who considered himself the voice of realism, but whom everyone else considered the pessimist - was looking forward to a relatively chore-free week. Sure, he would have to tend the horses and fetch the firewood, but he wouldn't have to clean Arthur's chambers; he wouldn't have to muck out; and he wouldn't have to carry the Prince's laundry up and down the five flights of stairs between his chambers and the launder. He was almost always excited by the prospect of leaving the bustling city behind for a few days. Of course, there was always the possibility that they would get attacked by a group of bandits, or a Questing Beast, or a rogue sorcerer, but Merlin almost preferred the action to his chores - as long as he was able to use magic, of course, and without getting caught. All in all, Merlin felt that, for a little while at least, he could relax and allow the knights to do their job.

So the warlock was dismayed - though not particularly surprised - when a great thunderstorm came quite suddenly upon the four travelers. They had been looking for a place to set up camp - or to attempt to do so, anyway - when they literally stumbled onto what appeared to be the site of several troops set up right on the border. This would have been quite wonderful, of course, if the troops had belonged to anyone but King Cenred himself. But as such an occurrence would have been far too convenient for the company, Merlin knew that it would have been impossible. So it was quite understandable that the four men would have taken a night out in the rain anytime over a night in this particular camp.

And because the odds were roughly twenty to one, it was also quite understandable that the same four men were now dry, but imprisoned by said troops. Currently, the scouts were waiting to be taken to King Cenred. They might have been let off with a warning, but unfortunately one of the men had recognized Arthur from a previous campaign, and so the soldiers were far too incensed by the fact that they had caught the Prince of Camelot unawares. So here the four sat, bound and surrounded, and with very little hope of escape.

"What are our chances of getting out of here alive?" asked Merlin, who seemed to be the only man who had managed to stay uninjured. Sir Leon had broken at least one rib; Arthur had taken a knife to the calf; and Geraint was nursing a bleeding head and quite possibly a concussion.

"Out of the tent or the camp?" asked Leon.

"Let's start with the tent."

"It actually wouldn't be too hard," said Geraint. "The soldiers are tired, and they are cocky. They've been trying not to fall asleep for about an hour now. As long as we're quiet, the tent shouldn't be a problem."

"And the camp?"

"All of the surrounding forest is probably under surveillance." This time it was Arthur speaking. "We might be able to escape into the mountains, then double back and head to Camelot. If we did that, we'd be able to skirt around Cenred's raiders entirely." It was actually a pretty sound plan - Merlin supposed that tracking anything was bound to be more difficult in the mountains, especially on a stormy night like this one.

"But how will we be sure which way to go?" the warlock asked.

"Don't be ridiculous, Merlin," Arthur practically whined. "As if I could get lost going to Camelot. Let's just work on getting out of the tent alive, shall we?"

Merlin grunted, not completely convinced but knowing that arguing would be futile. "I don't suppose you have that knife on you?" he asked the prince.

"In my boot. Can you reach it?" The four of them were sitting back to back so that they formed a wonky kind of circle, all facing outward. Each man was tied to the man sitting opposite him - Leon to Merlin and Geraint to Arthur. They were all on their knees - which was becoming rather uncomfortable - so that the person Arthur was addressing was the man to his right. Of course, the man to his right was Merlin.

"Can you move your foot back?" the manservant asked. He twisted as far as he could without dragging Sir Leon between himself and Arthur. Leon grunted as strain was placed on his rib, and Merlin muttered a soft apology. Arthur was doing the best he was able, but Merlin was still inches away from reaching the knife.

"Hurry, Merlin," Arthur huffed. "This hurts!" Merlin finally gave up; he reached deep down to that place where his magic was kept, and without uttering any kind of incantation, pulled the knife from the prince's boot. He was glad no one could see his face - he knew his eyes would have given him away.

"Got it!" he said with a sigh. He began sawing away at the ropes which bound Sir Leon's wrists. When the knight was finally free, Merlin passed him the knife and waited patiently while Leon worked on his own bonds. Then Leon passed the knife to Sir Geraint, who cut Arthur free and allowed Arthur to do the same for him. At last, all four men had been relieved of the painfully tight ropes, but kept up the pretense of being bound. They now waited for Arthur's signal. The prince was watching the bottom of the tent, where the guards' feet could be seen walking around the perimeter of their prison.

"Get ready," he muttered, moving into a crouch beside the tent-flap. The others followed suit.

"Now!" All four prisoners rushed out of the tent. Arthur, the only man among them who was armed, went first. The knights were sorely missing their swords - which had been confiscated upon their capture - and Merlin was already thinking of what spells he could use that would be effective but would not give himself away. In the end, the warlock settled for the tricks he normally employed - falling tree branches, flaring torches, men falling. The latter was especially easy, as the rain increased the likelihood of such an event occurring without his help. Between him and Arthur, the men who had been assigned to their tent were taken out quickly enough.

"On me!" Arthur called, dropping into leader-mode. Sirs Leon and Geraint flanked their prince, and Merlin fell into step behind them. They had no idea where their weapons, horses, or provisions were, so they had to abandon all three in favor of finding cover. Doubtless they were all far from pleased by the development, but they couldn't afford to stop and search for their supplies. The rest of the camp had already been alerted to the prisoners' escape - Thanks, Arthur, Merlin thought - and were rapidly making their way toward the Prince and his men.

Arthur led them through the maze of tents and fire puts until they reached the foot on the first great massif.

Merlin hated mountains. The few times he and Arthur had been forced to cross a mountain range, trouble had always been waiting for them on the other side. Besides, Merlin was clumsy on a good day. He really didn't need the help of a slippery mountain slope - in the dark - to prove that point. So he was quite loathe to go into this unknown chain of admittedly dangerous mountains when he was almost certain that they would end up lost anyway. And for some reason, Merlin could not stop thinking about the fact that he now knew what lay beyond these particular mountains, and he was not particularly keen on learning firsthand just how cold Narnia's Winter was.

Of course, his worries didn't stop Arthur from racing blindly into the mountains, nor did it stop the two knights from following their prince even more thoughtlessly. Merlin really had no choice but to run in after them.

Merlin wasn't sure how long they had been silently jogging through the strange valleys and hills, but eventually the dawn told him that it had been at least eight hours since their capture. They had been going at a gentle trot, but now the knights' injuries were beginning to take their toll. Leon was having trouble breathing - Merlin, who had broken his share of ribs, knew what kind of pain Leon was in - and Geraint was beginning to look dizzy. Apparently Arthur had cut his leg on something, and was now noticeably limping. Merlin himself had twisted his ankle at some point during the trek - and honestly, he was surprised at how well he was doing, given his history with… well, running. Still, he desperately yearned for a cool stream to dip his foot in. The rain still hadn't let up, which only made everything worse, though lightening had stopped making its way across the sky around the time they'd entered the mountains.

"Arthur, we all need a break," Merlin said. "I need to look at your wounds, and Leon and Geraint. They shouldn't have gone so long without being tended to."

"We're almost out of here," Arthur said, squinting. "See that green patch ahead? It must be the forests surrounding Camelot. I think we can make it; it can't be more than a mile or so."

"A mile is a long way for an injured man," Merlin protested.

"I can keep on," Leon said.

"Me, too," chimed Geraint. "I want to get out of these blasted mountains. I can go on a little longer." Merlin personally shared the sentiment, but Arthur's pallor was making the warlock nervous. Still, the knight knew his limits. They all did. And if they insisted that they could make it out of the treacherous ridge, then Merlin knew that they wouldn't listen to him until they had cleared it. Besides, all four of them were testy at the moment, and Merlin had no desire to be chastised or told to 'shut up.' So when Arthur declared that they would continue, Merlin huffed and sulked after them - though he promised himself that once they were clear of the mountains, he would insist, forcefully if he had to, that his companions allow their wounds to be treated. The warlock was already preparing a sleeping spell should he have to resort to more drastic measures.

It was another half-hour - though it felt like longer - before the company emerged into the forest Arthur had seen. Merlin looked around, expecting to feel that sense of familiarity to which he had grown accustomed when entering one of Camelot's forests. It did not come.

Arthur cursed. Merlin followed his gaze to the now-risen sun, glaring at them from the horizon.

They were facing East.

"Arthur…" Merlin started.

"Shut up, Merlin."

"…we're lost," Sir Leon provided. He was right; they hadn't doubled back as Arthur had planned.

They had gone straight.

They weren't in Essetir, and they certainly weren't in Camelot.

They had crossed the Eastern Mountains.