It starts with a letter from Elena which is mostly making sure that Arthur and Uther both understand that it was also her choice not to wed and she hopes that their families can still be good allies. There are a couple lines thanking Merlin and Gaius especially for the tonic which helped her feel much better than she had in years, and Arthur passes them on to Gaius and Merlin, who smiles just a little.
Or no. Maybe it starts with Merlin telling Arthur that it's probably a bad idea to go into that bar and have a tankard of mead with the locals. Maybe it begins when Gwaine asks for the jug and Merlin hands it over, their fingers brushing for a moment.
Do the beginnings actually matter, in the end? When you tell a story enough times, it smooths out into something that rolls off the tongue, with places for appropriate hand gestures and pauses for laughter. So let's try this again.
Once upon a time, in a place called Camelot, there was a boy named Merlin who was servant to the Prince Arthur. He was as magic as the sky is blue, but Arthur's father—King Uther—was not very keen on magic and had thus banned it because he felt that it corrupted the heart and was only a force for evil. Merlin did not find this to be true, but it was of little consequence what he thought, as he was just a servant.
Many miles away, in a place called Gawant, there was a somewhat clumsy and undignified Princess named Elena. The Sidhe had turned her into a Changeling when she was but a babe, and she now carried a Sidhe inside her, ready to posses her once the day she married Prince Arthur came. She did not know of any of that, however, and merely thought her unladylike behavior was due to her being different.
And at yet another location, there was a vagabond named Gwaine. He harbored a dislike of nobility in his heart, for they were the cause of much suffering in his life, even though he was noble himself. People often grew tired of Gwaine, and he moved restlessly as if he were searching for a place to call home.
I tell you of these three people, as different as they must sound, because they shared a bond quite unlike anything that has ever been recorded in Camelot's history, although no one says much of it at all. It is one thing for Prince Arthur to marry the Lady Guinevere, although that is tale enough in it's own right, and still another for a Princess, a Knight, and a servant to cross paths and fall into each other. I cannot tell you precisely where the tale starts or where it ends, but I can tell you of the fateful day when they all came together in Camelot once Prince Arthur had been firmly ensconced on the throne with Lady Guinevere at his side.
It was a celebration, you see, of the King and Queen's first child. Merlin was there because he was always by Arthur's side, even now that the danger was further and not so clear. Gwaine was there because all the Knights of Camelot were there. Elena was there because now that there was peace across the land, she and Guinevere had become good friends and she would not have missed such an occasion for the world. There was much laughter and drink and merriment on this day, of course, but the part that is important to our story is when Gwaine and Elena met.
You see, it wasn't uncommon for knights to never see the visiting guests of Camelot. They were sometimes away and sometimes training or guarding things. So, as it happened, this was the first time Gwaine and Elena had met, though he had heard much about her from Merlin and Guinevere alike. Gwaine was quite taken with the Princess Elena, and he wooed her with great enthusiasm. Well, to begin with he merely stared at her and sighed wistfully. It was Merlin who touched their foreheads together and told him that this was a new Camelot and perhaps it would allow for someone lower than a Prince to court a Princess.
Luckily for everyone, the Lady Elena seemed very charmed with Gwaine. Merlin was very happy for the two of them, although he seemed a little saddened by the whole affair too. You see, Merlin and Gwaine were quite close prior to Gwaine's wooing of Elena, and Merlin knew when he told Gwaine to go for it that it meant giving up what he and Gwaine had. The Lady Elena, however, was not the bumbling and somewhat cloud-headed girl that she had been when the Sidhe had inhabited her.
She saw the way that Gwaine looked at Merlin and she knew that it was not mere friendship between the two boys. Before she and Gwaine were to be wed, she pulled Merlin aside and smiled at him. Merlin, who was quite confused, asked the Lady Elena what she wished to speak to him about. Elena said that she knew that Merlin and Gwaine had a particular relationship and that she would not be adverse to it continuing once she and Gwaine were wed.
Merlin, who was not necessarily known for being the most articulate at the best of times, stumbled his way through his words until Elena gave a laugh and curved her fingers around Merlin's face, stilling him.
"Do not worry," Elena said, "It will be no hardship to me, and there isn't anything wrong with love."
It is said that it took Merlin some time to be won over, but that eventually he saw that there was no lie in Elena's heart when she said such a thing and accepted her offers. Eventually, they say, Merlin even grew to love Elena with a strong fierceness too, and that they stayed as happy as could be for the rest of their days.
There were fights, of course, but that isn't the point of the story. The point is that there is more than enough space in a heart to love two people if, like them, you are willing to work for it.