AN: This is my first attempt at both a crossover and Doctor Who fanfic. And Merlin, I guess. Enjoy!

When the Doctor first met him, he didn't pay him much mind. He was a young man at the time, and the Doctor had taken Martha to see a jousting tournament in 5th century Britain. He was helping a knight onto his horse, and took his weapons to polish when he stepped off. The Doctor and Martha only gave him a passing glance and continued to enjoy their outing. The boy's knight won, and the time travelers smiled along with him. Then the boy caught the Doctor's gaze, but only for a second.

It wasn't until the tournament was over that they learned his name was Merlin.

The second time the Doctor met him, it wasn't him at all. Jethro looked just like Merlin, albeit with black fingernails, but the Doctor quickly got over the shock and reasoned with himself; the universe was a vast and strange place. Look-a-likes were bound to happen. Maybe Jethro was one of Merlin's descendants. After the ordeal on Midnight, the Doctor departed with Donna and pushed Merlin from his mind for a long, long while.

The third time, the Time Lord wasn't sure it was him. It was 1847, and they were in a tavern, which was partially the reason the Doctor doubted his identity. That and he certainly wasn't the young lad from Camelot anymore; a trim beard obscured his face, and he resembled an age closer to forty or fifty. But that bright blue twinkle of his eyes, the one that made him so young and so old all at once, is what drew the Doctor to his table. They shared a friendly chat, and not five minutes later, both were doubled over in laughter.

Before he left, the Doctor asked his name.

He grinned, and replied, "Merlin."

And then he was gone.

The fourth time, he was positive it was him. According to Merlin, only a year had passed since their last encounter, so he looked much the same as he did in the tavern. The Doctor was all alone, so he welcomed the mysterious man's company. They enjoyed speaking to each other- there was always a tale to tell.

Up until then, it stood as a silent agreement between the two that neither was normal. The Doctor wasn't human at all, and Merlin was likely the same warlock from the Arthurian legends, but neither brought it up, out of respect for the other.

That night, they exchanged stories of their adventures. Merlin spoke of mythical beasts, dragons, knights, and a land of magic, to which the Doctor listened with a fascinated smile. In turn, the Doctor told the warlock about other planets, creatures from space, and all his companions past. Merlin heeded his every word, enthralled.

The Doctor offered Merlin a ride in the TARDIS when their conversation was finished. To his surprise, Merlin denied. He said he had to stay on Earth, in Britain, until a very important person came back. So the Doctor bid him adieu and slipped away into the stars, Merlin watching thoughtfully from the ground.

The Doctor had changed the fifth time they met. But then again, so had Merlin. His beard was longer and his hair was whiter, while the Doctor gained a younger face and a penchant for "cool" things. Oddly enough, Merlin recognized him anyway. They sat down to another tête-à-tête and the Doctor recounted his more recent adventures with Amy, Rory, and River. When he finished, he waited expectantly for Merlin to begin. Only this time, Merlin decided to indulge the alien, and did not talk about his quests or exploits; no, he talked about his friends. Arthur's unreasonable demands, Gaius's trusted advice, and even how Morgana's fall to evil broke his heart. The Doctor followed these stories with a sympathetic ear. He learned about Kilgarrah and Gwen, the Knights, and even Uther.

He let Merlin cry for a while before they hugged and parted ways.

The last time they met, it was the Doctor's turn to cry. The Time Lord had purposefully sought out the warlock this time, and the latter didn't disappoint. Merlin didn't press for information- he heard the Doctor choke out 'Amy' and 'Rory', and he understood just fine. They were sitting in the TARDIS, and Merlin made the obligatory 'Bigger on the inside' remark, which made the Doctor smile, just a little.

Hours passed, and it was time for Merlin to leave. The Doctor mutters a goodbye and stares blankly at the TARDIS console. Just as Merlin is about to step out of the box, he shouts to the alien.

"When Arthur comes back, we'll all go to another planet together." He hears the Doctor laugh and he closes the door behind him.

They haven't seen each other since then, but they know they will. And they look forward to it. The Doctor can't wait to talk about Clara, and maybe even introduce the two. Merlin looks out over the place the Lake of Avalon once was, and eagerly anticipates both of his friend's returns.

Somewhere in the universe, there are two very old, very wise men, whose paths sometimes cross. They told extraordinary stories and both were exceedingly kind. Their friendship began in a pub in the nineteenth century, but it all started in Camelot.

With a single glance, they made a remarkable bond.

And they do not intend to forget it.

AN: Waheeeey, done. Please tell me anything that needs to be fixed, and constructive criticism is greatly appreciated.