No spoilers or warnings, just fun and fluff. The idea of the knights and their alcohol-fuelled evenings out was too much to resist...

In Vino Veritas

Merlin was a watcher. He couldn't help it, it was just habit. No matter where he was or what he was doing, there was always something in the back of his mind, ticking over the actions and words of those around him. He analyzed, and drew connections; often without even realising he was doing it.

Gwaine liked to tell him that he had to turn his brain off sometimes. He said that because Merlin was forever running around cleaning up the problems of others, he'd made a habit of being in that problem-solving mode permanently. It was bad for his health and his peace of mind, and in the interest of health and safety he should therefore not be saying no to coming down to the tavern for a few drinks.

Merlin would grin, and shrug, and then he'd find himself sitting on a stool with a mug of ale or mead or whatever had taken Gwaine's fancy that night thrust in front of him. Gwaine would collect Lancelot, and Elyan, and Leon if he was in the mood (Percival was not a drinker, nor really a socializer), and it would be what Gwaine liked to call a 'Knights' Night'. He would grin madly at his pun, and everyone would groan, and a round of drinks would be ordered.

The first few times, Merlin let himself be swept up in it all, had drunk what had been put on the table and woken the next morning with a pounding headache and no will to work, something Arthur never failed to notice or use to torture him.

"You did this to yourself," Arthur would say dryly, and if Merlin protested there would inevitably be something flung at him.

So Merlin decided that maybe he should stop listening to Gwaine.

He didn't tell Gwaine that he wasn't drinking any more. He knew Gwaine would never take 'no' for an answer, so instead Merlin would accept a drink, and then somehow find a way to dispose of it – in a bush, perhaps, or by pretending to lose his balance and spill it. He even started a game of sneaking top-ups from his own mug into Lancelot's without Lancelot noticing, until he realized that Lancelot really didn't hold his liquor very well and perhaps this was being a bit cruel.

As the knights grew more loud and boisterous and less likely to notice Merlin's lack of involvement, Merlin would return to his habit of sitting and watching and making observations. He noticed that Leon had a great singing voice that worsened the more he drank, and that Elyan only pretended to like mulled wine. He learnt, from loosened tongues, that Lancelot had wanted to grow up to be an artist, and that Gwaine had taken to stealing cutlery from Arthur's kitchens for no reason other than that it was fun.

"I'll return it all one day," he'd said, sounding ridiculously pleased with himself. "In a huge pile on the kitchen doorstep. It'll be grand."

Merlin saw how Elyan was seen as something of a little brother, and the others would alternate between trying to throw girls at him and taking him aside for sage wisdom. He saw Leon's long-held gazes up at Albion Castle when they walked unsteadily home late at night, like he was searching the windows for a secret lover.

He took everything in his stride, all of it, until he started to notice something odd about two of his friends.

Gwaine and Lancelot had got on famously from the moment they met, which Merlin had wondered at since they were such different types. Gwaine was fiery and impulsive and game to laugh at everything that came his way, while Lancelot was thoughtful and well-spoken, living by a code of chivalry as seriously as one possibly could. After a few days of seeing them together, seeing Gwaine constantly making Lancelot laugh and Lancelot's ability to take Gwaine down a peg, Merlin had eventually chalked it up to the traditional 'opposites attract' adage. He watched them bicker and banter like an old married couple, which on Gwaine's 'Knights' Nights' (as Merlin was loathe to admit calling them even in his head) was always enhanced by the alcohol.

And then something began to change.

The first time it came to his attention was at the end of a long evening that had ended in Elyan serenading a beautiful woman before falling off a stool. Leon, who had managed to keep his wits about him, had volunteered to take Elyan home, leaving Merlin, Lancelot and Gwaine sitting around a wooden table finishing off their last drinks of the night (or in Merlin's case, slowly leaking his ale down the side of his chair and watching the runoff snake across the tavern floor).

"The beveran," Lancelot was saying slowly and pointedly, "is a type of rabbit, Gwaine. There is a difference."

"No," Gwaine responded loudly, stabbing the table with his finger. "It is a type of hare. I will prove this to you. I will go and catch one and prove it. Now. I'll do it now."

"No you won't," Lancelot said firmly, grabbing Gwaine's shoulder and pushing him back into his chair as Gwaine struggled to get up. "You cannot go hunting at this time of night, Gwaine. It is impractical. You will be eaten."

"By a monster," Merlin put in, hoping to speed Gwaine's new resolve to a hasty demise, and with it perhaps this pointless argument.

"Exactly, thank you Merlin," Lancelot said with a wave of his hand that nearly unbalanced him. He turned to Gwaine. "You see? Dead Gwaine is not preferable to me, believe it or not."

"I believe it," Gwaine replied quietly. The two looked at each other, smiling, and Merlin suddenly felt rather awkward and out of place, like he was intruding on a private moment. Which was ridiculous, he thought to himself. What kind of private moment would these two share? But he couldn't shake the curious feeling of missing something important as he stood up, cleared his throat and announced that it was time they all went home. As Gwaine waved goodnight and headed off in his direction alone, Merlin put the thought at the back of his mind.

It was not long, however, before he was forced to take it out and re-examine it.

Two nights later there was a party, held by Uther for a visiting King on the eve of the signing of a treaty. Arthur had explained to Merlin at great length what the treaty was about, but it had slipped through Merlin's mind like sand. He had more important things to catalogue. Like Uther's flirtatious banter with the visiting King's wife, and Leon standing on his own looking concerned about something Merlin couldn't deduce. And the fact that Arthur had actually just fetched a glass of wine for both himself and Merlin, which apart from shocking Merlin into the next century also meant he couldn't possibly turn it down.

Gwaine had burst into the room like the celebration was his own, his deep red ceremonial cape swirling behind him, and swanned over to Arthur and Merlin, cutting a swathe of swooning women in his wake.

"Gwaine, you made it," Merlin said happily, and Gwaine laughed.

"I cannot for one second imagine that you entertained any doubt about my attendance, Merlin" Gwaine replied, snatching a flute of something sparkling off a passing tray. "If you did, I'd have to believe that you really don't know me very well."

"Fair point," Merlin conceded, taking a sip of his wine and trying not to pull a face at its unusually high concentration of alcohol. He noticed Arthur watching him over the rim of his own glass and grinning ever so slightly. Merlin didn't know what to make of that.

"Ah, Gwaine, don't you look dashing," came a wry voice from behind them, and the trio turned to see Lancelot approaching. "Never one for subtlety, are you?"

"Lancelot, if an occasion permits me to wear a cape then I shall damn well wear one," Gwaine responded gamely, clapping his friend on the back with a grin that Lancelot returned.

"Well I can only hope you will be gracing us with a number on the dance floor then. Seems only fitting for such a bold and lively garment," Lancelot replied, taking Gwaine's drink from him and sipping from it with such casualty that Merlin felt his eyebrows shoot up. As memories and their accompanying confusing thoughts from the last Knight's Night returned, he hoped the pair hadn't noticed his surprise. Perhaps it was somewhat telling that they were too interested in each other to have done so.

"As you wish," was Gwaine's answer, and Merlin didn't miss the underlying note of affection.

With that, he disappeared into the crowds.

"Oh, Maker. I find myself regretting this already," Lancelot muttered to his friends, and Arthur laughed.

"Yes, you seem to have set something in motion. I find myself amazed at your power over the man. If I could command him like that, getting him up for training would be a lot easier." Arthur's tone was glib, but Merlin saw a curious expression flash across Lancelot's face in response. Something akin to gratification, but lacking any trace of self-satisfaction. Contentment, that was it. Lancelot had looked contented.

Before Merlin could dwell on it further, or try to fit it into the emerging puzzle that was Gwaine and Lancelot and whatever was going on between them, the music changed and the crowds had parted. They saw a flash of red out of the floor as Gwaine appeared, whirling into view and leading a chain of people in a round. Laughter and cheers erupted from the crowd as more and more people joined in, and the dancers gradually picked up speed along with the music.

"Merlin, if I commanded you to dance for my amusement, would I hold the slightest chance of seeing that actually happen?" Arthur asked lightly. Merlin grinned.

"Not even with the threat of extra chores, Arthur."

"Ah. Well, more wine into you it is then." It was Arthur's turn to disappear, presumably off in search of a drink.

"That was oddly relaxed of him," Lancelot remarked, still sipping from what had been Gwaine's glass.

"He's been practically pleasant all evening. I can't imagine why. Although I'm beginning to suspect he cracked open the wine a bit earlier than the rest of us," Merlin suggested thoughtfully.

Gwaine burst out of the crowd in front of them like a hurricane, short of breath and beaming. He came to a halt, planting himself in front of Lancelot.

"Come dance," he ordered, but Lancelot shook his head.

"Maybe in a bit."

Gwaine sighed dramatically, but shrugged and was off again as a new song struck up.

"Does 'maybe in a bit' translate to 'not on your life'?" Merlin asked, and Lancelot glanced at him.

"It would if it were any other person. Gwaine, on the other hand…"

"Gwaine will hold you to it," Merlin finished, amused.

"It's not that. It's more that… he actually makes me want to dance," Lancelot replied, attempting to sound airy and failing miserably. Merlin could not stop himself from staring at his friend, his mind turning circles. Lancelot cleared his throat. "I think I have had far too much wine, Merlin."

Merlin barely had time to glance at Lancelot's half-finished glass, the same one he had been sipping at all evening, before Arthur reappeared beside him and forced a fresh drink into Merlin's hand. "Bottoms up, Merlin."

Merlin fingered the tumbler reluctantly. "Arthur, you know what wine does to me. If you're going to punish me tomorrow…"

"No. I'm declaring tomorrow a public holiday. For you." Arthur raised his own goblet as if in toast, and started to down it. Merlin stared wide-eyed and Lancelot chuckled.

"Now I know someone has had far too much wine," Lancelot muttered in Merlin's ear. "I think your theory might have been right. Enjoy it while it lasts."

With that, he knocked back the dregs of his drink, set his cup down on a nearby table and set off in the direction of the dancers.

The following morning Merlin was stunned to find that not only did Arthur remember his promise of a day off, but stayed true to it, leaving Merlin to lie in bed trying not to be awake until Gaius had tromped into his room and flung open the curtains with thinly disguised glee.

"Get up, Merlin. It's lunch time," he declared, unnecessarily loudly.

When Merlin's head had settled and he had forced down some food and a lot of water, he found himself able to think again, and his mind went straight to its most curious topic. Two nights were not enough observing time to draw any kind of concrete conclusion, but Merlin could not do anything to subdue the nagging feeling that something entirely out of the ordinary was going on with Lancelot and Gwaine. The affection, the banter; he supposed he could put it down to Gwaine, who made a habit of flirting with anything that moved. It was basically just how he communicated. But that didn't explain Lancelot's admission last night.

There was a possible answer to it all, he thought now. An odd answer, an unprecedented answer, but an answer none-the-less.

"They're in love," he said out loud, as if daring someone or something to prove him otherwise. But nothing answered him, and Merlin felt a familiar feeling sweep over him, the feeling of an idea being set in concrete. The more he ran it over, the more he was sure he was right.

But he was an observer, and he knew of only one way to prove it once and for all.

He had to watch them.

The next day's training came quickly. In between fetching equipment for Arthur and occasionally being used as a training dummy substitute ("The wooden ones don't have your spirit, Merlin," Arthur would say dryly), Merlin tried to pick up on anything between Gwaine and Lancelot. The two paired up and split off when it was necessary, and bantered a fair bit all the while, but nothing about their actions screamed 'clandestine lovers'.

The next time he saw them was at the tavern two days later as Gwaine tried to round up another Knights' Night. Elyan was game, having missed the party earlier that week, but the others were still haunted by memories of mornings after and no one lasted more than two or three drinks before packing it in. The mood had been subdued all evening, and with still no fresh fodder for his theory Merlin called it a night.

Three weeks passed, and nothing happened to reassure Merlin that he hadn't imagined the whole thing. The two bickered like normal, made each other laugh as normal, and although Gwaine occasionally made flirtatious jests towards Lancelot it was no more so than he did for anyone else.

And then Festival was upon them, and Camelot came alive with colour. Lanterns were strung up and let loose, scarves hung out of windows, and musicians gathered on street corners to strike up impromptu concerts. The city was alive with visitors; some come to hawk their wares and others just for the celebrations. It was three days of excitement and revelry, and the accompanying nights were lit with merriment.

Merlin, to his annoyance, spent the first two evenings engaged in official activities. Arthur required him to wait on the opening night's court feast, and be on hand for the second's ceremony that saw the royal family receiving commoners. He grumbled to Arthur, and had a pillow flung his way.

"I'm stuck inside these walls too, Merlin. At least you don't have to spend the entire evening looking like you want to be there."

The third and final night could not have come fast enough, and as the sun began to set Merlin was free to join the city in its festivities.

"Mer-lin," came a lilting voice as Merlin was exiting the castle grounds. He glanced over to see Gwaine striding towards him, decked out in black and silver complete with mask and feathered hat. Merlin thought that if he himself wore such a thing he'd look a complete fool, but somehow Gwaine managed to carry it off with aplomb.

"The swashbuckling look suits you," Merlin said approvingly as Gwaine eyed his own clothes.

"And what are you dressed as, a servant? Not terribly imaginative, Merlin," he replied, grinning. Merlin shrugged.

"Me, in costume? Not something I'd live down any time soon."

"If you say so," Gwaine laughed. "Have you seen my other half?"

"Your – wha?" was all Merlin could get out before Gwaine's eyes lifted over him and he beamed.

"About time. You take far too long to get dressed," he called to someone behind Merlin.

"I'm sorry, have you seen the amount of buckles on this thing?" came the response.

Merlin turned to see Lancelot walking towards them, dressed as a pirate captain and looking slightly self-conscious in his own costume. He needn't have, Merlin thought, very much impressed.

"See Merlin? This is what Festival is about. Impractical yet inspiring outfitting," Gwaine remarked, flicking the plume in his broad-brimmed hat. Merlin couldn't help but laugh.

"Don't worry, Merlin," Lancelot interjected. "Elyan wouldn't dress up either, and Leon's just wearing his armor and heraldry."

"Which was your original plan if I recall," Gwaine said sourly. "What did you lot do without me?"

They wound their way through flocks of people and found Elyan and Leon in the town square, attached to a group that was enjoying a performance from a knife juggler in a gold dragon mask.

"Impressive," Lancelot remarked as they joined the throng.

Elyan nodded as the knife juggler finished his display with a final flourish. "He's very talented. I wonder if this is how he makes his living?"

Merlin listened and smiled to himself. As the juggler began to put away his knives he sidled up the man.

"You don't think a dragon mask is just a tad unsubtle, sire?"

Merlin watched the man's eyes widen behind his mask.

"How did you know it was me?"

In a moment of clarity, Merlin foresaw the ridicule an admission of "I recognised your eyes" would bring, and instead went with, "I saw the mask while cleaning your room, Arthur."

Arthur stared at Merlin for a few seconds. "Shut up Merlin."

"Did I say anything?"

"You were going to."

"Of course not. I just didn't know you went to bed every night dreaming of being a circus performer."

Arthur sighed. "There was kid who was upset, and I thought I could cheer him up. I certainly wasn't planning on…this…" he gestured at the now dispersing crowd. "I guess it all just got a bit carried away. Wearing a mask does odd things to your sense of proprietary."

"If you say so," Merlin replied, barely stifling a laugh, and Arthur punched him on the arm, but gently. "The others are over here. You might want to remove that mask."

Arthur glared daggers at him, but had to concede that Merlin was right. He briskly untied the mask and shrugged a coat on over his clothes, before allowing himself to be lead across the cobblestones.

"I have our prince," Merlin announced as they approached, and was met with cheers. "May I ask what our first stop is?"

"Mead!" Gwaine declared happily, pointing at a vendor across the square.

Merlin was not quick to forget himself this evening, not like at the last event of such magnitude. As the night wore on he fell into his usual routine, letting the others do the drinking while he looked on, wondering if maybe this time he could put to bed once and for all his questions regarding Gwaine and Lancelot.

It was chance that finally put an end to Merlin's mission.

The night had passed into the early hours of morning, and Merlin found himself the shepherd of a rather drunk crew of knights. They had finally come to a halt in a small square somewhere near the market district, with Leon slumped against a wall and Elyan on his back on the flagstones. A few feet away, Arthur was sitting on a pile of bricks, apparently playing with some ribbons he had picked up. Merlin didn't know where the others were and hoped they weren't unconscious in a ditch.

"I have no idea what I'm going to do with you," Merlin muttered, more to himself than to any one of his friends.

"I'm quite fine here actually," Leon murmured drowsily.

"Mmmm," agreed Elyan without opening his eyes. "Not feeling great. Don't really want to get up. Ever again."

Merlin sighed. "I'll get you some water. Stay."

"I'm really, really not going anywhere," Elyan responded, and Leon giggled. With a glance over at Arthur, who was still entranced with his find, Merlin set off to find the nearest well. The crowds had thinned considerably but there were still significant amounts of people who roamed the streets, some trying to get home and some still carrying on as if there was no tomorrow. Merlin rounded the corner and made for a side street he knew to be a shortcut.

And then he saw them, two figures in a cobblestone alley. Lancelot had his arms around Gwaine's neck, and they seemed to be talking intently. Merlin stopped dead, half in light and half in shadow, hoping they wouldn't turn his way. He looked on as Lancelot said something and Gwaine threw his head back and laughed, and then they were kissing, slowly and sweetly.

Merlin felt his cheeks burn, watching them. A funny kind of joy swept through him, and he wondered briefly if it was from a sense of victory. His theory was well and truly proven now, that was part of it. But more than that, it was happiness for his friends. He felt pleased that they had each other.

That was it, then. Operation over, proof discovered. No one else had to know, if that was what they wanted. He would keep their secret for as long as they needed him to.

"Merlin?" said a startled voice in his ear. "Is that-"

Merlin felt his sense of purpose deflate ever so slightly. "Yes, Arthur."

"Are they-"

"Yes, Arthur."

"Are we supposed to know abou-"

"No, Arthur." Merlin turned, and grabbing Arthur by the collar he dragged him up the street.