Arthur has an imaginary friend.

He's not like most imaginary friends—or at least Arthur thinks it's a he. He doesn't know for sure, because he never sees his imaginary friend.

His imaginary friend is invisible.

He's been there for as long as Arthur can remember. In fact, if he could remember being born he's sure he'd remember his imaginary friend being there too.

He calls his imaginary friend Emrys.

It's a name that came to him in a dream. He has funny dreams sometimes. He's always back in the Middle Ages, which he likes, and he always has a sword, which he also likes. But he can't remember any people.

The worst one is where he wanders through a castle. He knows the castle, every bit of it, but no matter how much he searches he can never find anyone. He's in an empty castle, all alone.

But it's all right. Whenever he wakes up, scared, Emrys is there. He can feel him, just out of reach, all comforting and strong, and Arthur knows nothing will hurt him, not with Emrys there.

He tries telling Father about it, but Father just gets angry and tells him that the Prince of Wales does not have an imaginary friend.

He tells his sister, though. His sister is very understanding. Sometimes, he thinks she's too understanding, because she looks at him with her big gray-dark-amber eyes and there is so much sadness and regret in them that he's not sure she's not secretly a thousand years old.

But his sister is also very smart (and a whole year older) and she tells him to stop talking about Emrys.

"People won't understand," she tells him. "They'll think you're making it up."

So he stops talking about it.

After a while, he forgets about Emrys. He has a lot to learn as the future King of England (unless Father decides to live forever). He's first in line because his sister is only his half sister. She has a different father. So she can't be queen. Which she says is fine, she doesn't want to be queen, she tried that once and it didn't work out.

Arthur's sister is very strange sometimes, but he loves her anyway.

A little while after he starts to forget about Emrys, Emrys stops showing up. Arthur doesn't notice at first. He's too busy with public appearances and lessons and being shunted from one place to another and dealing with Father and trying to be the good kid because the position of disobedient kid is already filled by his sister.

But then he does notice. And he's sad. He knows it's his fault. He pushed Emrys away. He stopped caring. He cries for hours after that, and his dreams are full of strange and horrible creatures, and a woman's cruel laugh. He's scared, really scared, for the first time in his life and he cried out instinctively and suddenly Emrys is there. Arthur can't feel Emrys the way he can feel his sister when they smack each other or hug each other but he can still feel in a different way. And Arthur feels safe, because he knows nothing will hurt him. Not with Emrys there.

Emrys doesn't stay all the time like when Arthur was little. Arthur understands. He has to be an adult, and adults do things differently. But whenever he's feeling hopeless, like when he's sixteen and he realizes that he thinks boys are just as attractive as girls and he wouldn't mind kissing one, and he nearly throws up because he knows Father will never understand—Emrys is there.

Or when he's eighteen and he just knows he's flunked his test, and he doesn't ever want to leave this bathroom stall, really, he's just fine dying slowly in here—Emrys is there.

And now he's twenty one. He's officially, well, an adult. It's his coming of age ceremony or whatever Father feels like calling it.

Arthur looks at himself in the mirror. He looks great, he knows. The red tie is out of the ordinary but it'll definitely draw the eye and who said men had to wear all-black, anyway?

He feels like vomiting, or maybe running away and living as a hermit up in the hills of Scotland.

Arthur clears his throat. He's never done this before, but then Emrys has never taken this long to show up before.

"Emrys?"

He has never, not once, talked to his imaginary friend. He's called him Emrys plenty of times, but only in his head or the one time when he told his sister about it. He's certainly never had a conversation with Emrys before.

"Listen, I know you're there. Somehow." Arthur stares at himself in the mirror, resolute but terrified of what he'll see when he turns around—if it'll be a horrendous dark faerie like in his sister's childhood books or, even worse, nothing at all.

"I want to see you. Please."

Still nothing.

Arthur sighs. "Look, it's my twenty-first. The whole world is staring at me. Father expects me to be—I don't even know anymore. Someone I'm not. I don't know who I am, I haven't got a clue where to start, but I sure know what I'm not and that's Father's clone. I just… you're always here, always there for me when I need you, and I need you now."

Arthur can feel something behind him—a presence.

He wants more than just a presence.

"I know you're not really invisible. I want to see you."

Something in the air shifts subtly, and Arthur heaves a relieved sigh. "Thank you."

There's a startled hitch of breath, like… like someone hearing a ghost speak.

Arthur turns around.

A young man of about Arthur's age is standing in front of him. He's wearing jeans and a dark shirt and two handkerchiefs, one on each wrist: blue and red. He's got a necklace on which hang two rings. One is silver and rather simple. The other is also silver, but with a gold band on either side, and strange runes carved into it. It looks like very ancient writing. And on the ring finger of the man's left hand is a third ring. It's a massive, silvery dragon ring, and it's quite possibly the greatest piece of jewelry Arthur has ever seen—and that includes the crown jewels. Whoever carved that ring was a master.

The man has very dark, sort of floppy hair, an angular face—an angular body, really—a slightly pointed chin, disarmingly large ears, a somber mouth and bright, blazing blue eyes. The man looks young, but like his sister there is so much sadness and regret in those eyes. He looks like he has had all of history placed upon his thin shoulders, and Arthur wants to take that misery away from him.

Arthur feels like he's back in his old nightmare about the empty castle, only this time he found what he was looking for.

"Who are you?" Arthur asks, even though it's a silly question because he knows who it is, it's Emrys.

"You call me Emrys, and that is one of my names," the young man replies, "But it's not my original name."

"And what's that?"

"Merlin."

Arthur feels a brush of lips. First on his forehead, and then pressed against his own. They were warm, and soft, and he clung to them.

And then all was nothing.

And he remembers.

"Merlin?" His voice is a whisper.

Merlin stares at him with that stupid, ridiculous, wonderful idiotic look of gaping surprise. "What?" His voice is rather strangled.

Arthur crosses the few feet between them, wrapping his arms around Merlin, kissing him for all he's worth. He can't even think properly, his only thought being this, this, this. Merlin can't stop touching him everywhere, his hands pressing and sliding and fluttering from place to place, and Arthur realizes that Merlin spent twenty one years waiting, wanting but unable to take, to touch.

"I missed you," Arthur admits, his mouth brushing against Merlin's because that's as far as he can stand to be apart from him right now.

Merlin lets out a strangled sob. "I missed you for a thousand years, you clot pole!"

And Arthur laughs, and kisses him, and kisses him, and kisses him again.