A short Harry Potter x Merlin One-Shot based on this post: mamalaz dot tumblr dot com/post/82302915105/mirror-of-erised-merlin-au-while-merlin-is-a

This is not Murther, (sorry if you wanted it to be) but more long lost friendship. Enjoy!

Merlin wandered down the halls of Hogwarts, just as he did every evening since he had arrived there three weeks ago. Many centuries had past and as Merlin walked he wished that Arthur could see this castle, it was absolutely spectacular, albeit a little magical. Arthur would accept that now though. That's what Merlin hoped anyway.

The halls were quiet, only a couple of students wandering about back up to their dorm rooms. The room that Merlin was after was at the end of the corridor. When he reached it he looked around before entering.

Inside was pretty spartan, nothing much lined the tall stone walls and only one object stood in the room: the Mirror of Erised. He walked up to it, as he had been doing and smiled when he saw the reflection. Arthur, as in the Arthur that wasn't dead that hadn't been killed by Mordred or the Arthur who couldn't be saved by Kilgharrah. No, this Arthur was alive and smiling. He didn't talk, but he stood tall, as the good king should and looked back at Merlin. This was his only way to see him. The first night that he'd discovered the mirror he had broke down in tears, telling the virtual Arthur how sorry he'd been that he was unable to save him, telling him that he should have done more, or even revealed his magic earlier so that he hadn't been injured in the first place.

But now, now he sat calmly in front of the Mirror and told him about his day.

"Back again, old friend?" came a voice behind him. The voice sound like that of his persona of Emyrs, old, but wiser. Merlin spun round, slightly startled. It was Dumbledore. "I know you come here every night, Merlin." He told him.

Merlin was taken aback by the comment. It wasn't like it was a secret or anything; he just wanted to be alone.

"I…" He started, but Dumbledore shook his head.

"You see Arthur Pendragon, do you not?" He pondered, even though he knew he was right.

"Yes." He replied shortly. Merlin took a glance back at the mirror; Arthur was still there moving ever so slightly. "I just wanted to speak to him, nothing more. Destiny failed me and I couldn't save him. It was my fault." This was the first time Merlin had actually told anyone about it.

"I know." He told him. "But it's all alright, I'm sure Arthur understands that you tried and you can do nothing more than that. Come here," Dumbledore said, beckoning towards him. Merlin did so and they both started walking out of the room, the image of Arthur disappeared in a water-like ripple and the mirror was then just a mirror.