A/N: First fanfiction! Never intended to write fanfiction, and certainly did not intend for my first attempt to be this big of a project, but these things happen. I'm really trying to improve my writing and editing skills, so constructive criticism is encouraged. Thanks for reading!

This story is based on a translation of 'Sir Gawain and the Green Knight', but more focused on Gwaine, Arthur, and Merlin as a team, rather than only Gwaine, and takes place after season 4

I don't own BBC Merlin, nor do I own the story of Sir Gawain and the Green Knight.

The halls were filled with the castle staff bustling around preparing for the feast. The Grand Hall needed decorating, visiting Lords and Ladies needed clothing, and grand spread of food needed preparing. A young servant boy ran down the halls, squeezing through people and nudging them aside where he could, nearly plowing over a maid carrying fresh laundry. Finally, he came upon the hallway to the royal chambers: deserted. No servants were bustling through that hall in particular to help the king dress and prepare even though the hour of feasting drew near. That is, none until the young servant sprinted his way down the empty hall to the king's chambers. He burst through the entry, smacking the door against the wall with an obtrusive and unpleasant bang. The servant looked around for his master, panting. When he saw the room was empty, he nearly heaved a sigh of relief. Perhaps even Arthur was running late.

"MERLIN!" Arthur yelled from behind the changing screen, dashing the servant's hopes. "You idiot! Where have you been? The New Years' feast is going beginning soon and the king can't show up late!"

"Sorry Sire!" Merlin made his way across the room, cheeks scarlet not only from the run. "I forgot that I had left your ceremonial sword in the armory for polishing, and then Sarah needed help carrying Gwen's gown up from the royal seamstress' room to her chambers, that thing ways a ton with all that fabric and those decorative beads, and then I heard an awful smashing noise coming from the kitchens and–"

"Don't be ridiculous Merlin, just get me dressed before you make me any later than I already am."

"You know, if his royal highness knew how to properly dress himself then this sort of situation wouldn't happen"

A heavy fabric was thrown out forcefully from behind the changing screen, somehow expertly landing on Merlin's approaching head.

The most beautiful ladies of the land, and the most handsome lords gathered in the Grand Hall at Camelot to revel in the spirit of the New Year. They talked, laughed, and often snuck off to the farthest and emptiest reaches of the castle in pairs. They danced for hours, ate, sang, and drank in their revelries, when finally the main dinner was served. Arthur refused to eat until everyone in the hall was served, an annoying habit of his, in Merlin's opinion, but a commendable and honorable one in the eyes of others. With the delicious meal completed and the guests itching to begin late night drunken festivities, a toast was in order. Something that never ceased to amaze Merlin was Arthur's ability to silence a room. He rose from his seat, holding a goblet in his hand and almost immediately the crowd hushed and gazed on with admiration and their utmost attention. It was moments like this that Merlin remembered why Arthur was his king. Where Uther's people and crowds were silenced out of fear, Arthur's people were silenced out of devotion and respect.

"To my loyal knights on this fine evening. Your work this year has not been overlooked, I thank you for your bravery and loyalty in the face of danger, and I hope you find the chance to have some fun tonight." He looked at the still-sober knights at the head table, all of those he was closest to. A few chuckles arose when Gwaine smiled and tipped his chair back so it was balancing on two legs, fingers locked in a leisurely pose behind his head.

"To my beautiful wife, I don't know where I would be without you Guinevere, you have brought me the best year of my life. Camelot would have surely perished under my rule if not for you advising my and keeping my head level." A few 'oohs' and 'awes' were mumbled throughout the crowd while Arthur looked at his radiant wife. Merlin swore he saw twinkles in both of their eyes, and rolled his own in an attempt at mocking, but wasn't successful because of the proud smile he wore.

"And to the amazing serving crew who worked tirelessly for weeks to put together all that you see here tonight. Tomorrow you shall all receive a day of rest to spend time with your families." The servants in the room smiled adoringly at their king, then proceeded to exchange their hushed exclaims of excitement amongst each other. Merlin knew he wouldn't be getting the day off tomorrow, the king wouldn't survive without him, after all, how would he dress in the morning? Surely not by himself. The toast was not meant for him but rather the staff that helped prepare for the feast. Arthur was completely unaware that Merlin spent all of his free time in the last few weeks helping preparations in any way he could. The extra work preparing for the holidays coupled with Arthur's increasing demands when put under the stress of the Christmas and New Years' feasts made a very exhausted Merlin.

The crowd began to clap for their king and everyone rose from their seats to show their respect. It was then that the court was most vulnerable. It was then that the Green Knight acted.

The heavy hall doors swung open with a bang, nearly breaking off their hinges when in rode a knight on horseback. The guards inside the door were thrown from their posts while the guards previously sentinels outside scrambled in after the intruder with wide eyes and trembling swords.

The knight and his steed were one of the most peculiar things to arrive in Camelot. The knight wore no armor, no helmet, nor shield, yet he carried the most enormous axe that Merlin had ever seen. He was fully clothed in green. His cloak, trousers, tunic, gloves, and boots all fashioned the same color of deep green. His hair and scruffy beard matched the hue perfectly, and his horse followed suit, its mane and tail also colored the unnatural shade. But probably the most unusual anomaly was the size of the pair. Even Percival would have been dwarfed by the giant knight that stood before him, the horse made those in the royal stables look like ponies.

The lady's and elder lords of the court quickly backed away from their tables, scared and weary towards the foreign man. Knights of every rank tensed and withdrew their swords. Merlin move purposefully closer to Arthur who was now standing, tensed and ready for any kind of attack. He scanned the room until he met Gaius' eyes, ensuring he was a safe distance from the potential threat.

"Where is the noblest of all of this crowd?" The Green Knight's voiced boomed through the hall. "I'd like to speak to him in particular, to exchange some words politely." He made no offensive move.

"Sir, you are welcome to dine and stay with us. I am King Arthur of Camelot, and it would be a pleasure to have you as a guest to our household" Arthur said cautiously and politely, though still palmed the hilt of his sword.

"No thank you sir, I do not intend to stay long. My purpose here will be over soon. The tales of the courage and strength of the Knights of Arthur's Round Table have spread far and wide. Rest assured, I come for peace, not for battle, however I do wish for an exchange."

Merlin saw Arthur hesitate in confusion and sympathized with him. No one had ever seen such a spectacle, no one had ever made such a strange request. Magic Merlin thought, and knew the same word was going through Arthur's head.

"What exactly are the terms of this exchange, sir knight?" Arthur finally continued.

"I come to test your court, King Arthur. Your knights are revered as heroes, your people as faithful, your queen as strong, and your sorcerer as devoted."

"My sorcerer?" Arthur lost his composure in confusion, stumbling through the word and eyes widening. Merlin made a quiet strangled noise of shock behind him.

"This is a challenge, young king." The giant continued, ignoring Arthur's question. "This is a challenge to all who devote themselves to you. A challenge to your knights, your people, your queen, and your Emrys, who each have reputations spread throughout the land. I will give whomever is bravest in your court my axe, and he shall deal me the first blow with no retaliation from me. However my terms dictate that in exactly one year and a day, I am given the chance to return said blow."

The hall fell silent, everyone standing in confusion, and the Green Knight waited, dismounting from his horse.

"No one volunteers themselves as the most courageous knight in the kingdom? Oh how disappointed am I!" the knight paced slowly back and forth. "No worthy knights? Not even Emrys offers himself up to this challenge?" Merlin tensed, his breathing stopped.

"If you want a duel, I will accept your terms" Arthur said powerfully.

"Arthur no, he's magic, it's a trick." Merlin whispered from behind, Arthur heard him and whispered a quick "Shut up, Merlin" without removing his gaze from the Green Monstrosity.

'Oh the strong and courageous King Arthur volunteers himself. I am disappointed though not surprised. Very well, you shall prove your worth instead of that of your people." He said with finality.

Suddenly there was a violent scraping as a chair was shoved back and its front legs slammed towards the ground "This is ridiculous, the king shouldn't have to stoop to this trivial game." An unconcerned Gwaine stood from his disregarded chair "I accept your challenge." And he made his way around the table to face off.

Merlin bit his lip hard, preparing to intervene in any way he could, magically or not. Gwaine's life was not worth him keeping his secret, a lesson he had learned years before with the sacrifice of Lancelot. Arthur nodded his head respectively toward the knight, and the nod was returned.

"A single blow with my axe," The Green Knight repeated, offering his hilt to Gwaine, "And in a year and one day, you will come find me at the Green Chapel, and I will return the blow and you will receive it without fight."

"I will, that is, unless I kill you." Gwaine said, taking the hilt, gripping the heavy weight with both hands.

The Green Knight stood tall, awaiting. Gwaine looked at the axe in his hands then looked at the Green Knight, and hesitated. All of a sudden he reared back, a snarl on his face. His arm swung true and sliced right through the Green Knight's neck. The giant's head fell clean off his body, falling to the floor with a thump. Everyone waited with baited breath for the body to fall with it, but it never did. It just stood still, unmoving. Gwen gasped and gripped Arthur's arm beside her when the body suddenly moved. It was not falling to the ground in death however, it was reaching down as if still alive to pick up its own head. Gwaine cautiously moved back as the headless knight straightened himself. Merlin tensed, suddenly sensing a magic in the room that could rival Morgana's or even his own. The Green Knight's hands turned his head toward Gwaine and everyone in the room gasped when they saw that his eyes were still open.

"I will see you in one year and a day sir Gwaine." And with that the Knight expertly mounted his horse with his own severed head tucked between his side and his arm. Him and his horse turned toward the door and barreled through the half-hearted attempts made by the guards to keep him from leaving.

As soon as the door slammed shut, Arthur jumped into action. "Leon, gather a squadron of knights and follow him, now." Leon hastily and expertly followed the orders, each and every round table night springing to action. Arthur turned toward Guinevere next and with a quiet voice, ensured she was alright, taking her face into his hands and looking for any sign of panic in her eyes. She unexpectedly swatted his hands away.

"Arthur I'm fine, it was a bit of a fright but you have more important things to take care of." They shared a look of understanding, a look that anyone with a responsibility to others would understand.

Arthur then turned to Merlin. "Feast is over, make sure everyone remains calm and gets safely back to their rooms." Merlin nodded and got to work, pausing only for a moment to see Arthur approach a stone still Gwaine holding the axe, and put his hand on his shoulder.