Bonus points if you get the Doctor Who reference (it's not very obvious but still)

Cas POV

It had been a week since Cas had met Merlin and he'd felt guilty ever since then for not going back, but between the Winchesters and looking for what he needed he hadn't found the time. And now finally, after days of searching he'd found it.

"Merlin," he appeared in front of the warlock suddenly and out of nowhere, startling him.

Despite his shock however, Merlin smiled, "Cas!" he greeted his friend, "I was beginning to think you weren't coming back." His voice was joking but you could tell he meant it.

Cas smiled, "regrettably it did take me a long time to return, but I can assure you it was worth it. You see, I was thinking about your little problem and I've found a way to help you." He took out of his pocket an unusual looking necklace. It was made of a black metal and it was formed in the shape of a pentagram. Merlin took the necklace and put it on and instantly Castiel felt better.

"You see," Cas explained, "that's an ancient metal, it was used by witches in the days before even I can remember. They used it to control their powers if they ever needed to speak with us and I supposed it would work with containing yours too. It seems I was right, because I can't feel your magic interfering anymore."

A wide smile spread across Merlin's face. "Really? So it's all fixed now, no interference or anything like that, and I can still do my magic?" Just to test it, he lit a small flame in the palm of his hand. "Thanks Cas."

Looking pleased, he elaborated. "On the witches in the old days it completely prevented their powers from working, but you're stronger than that so they'll work even if you're wearing it."

Merlin was still beaming. "Why that shape?" He inquired.

"Well it had to be in some shape so I thought I'd make it a useful one; it stops you from getting possessed." He felt the need to add, "Also because Dean insisted."

Now Merlin was interested in Castiel's life, the angel knew all about him but he knew nothing of the angel. "You never really told me who they were you know, Dean and Sam Winchester. You said you rescued them from hell and that you had to protect them but that's all you said."

Cas pointed to a chair before he started to explain. "Have a seat Merlin this might take a while."

Merlin POV

In the next few months, Cas visited Merlin almost every week. Each time they met they exchanged stories of their lives, or sometimes they just enjoyed each other's company until the Winchesters got impatient and called him back. Sometimes they sat by the lake, which Castiel discovered was called Avalon and sometimes they stayed inside Merlin's cabin home instead. Some weeks Cas never turned up, and on those weeks Merlin never wondered why he wasn't there, he worried about what could be so bad to keep him away, but no matter how long it took Cas always came in the end and the two developed a close friendship.

But one other thing had been plaguing Merlin's mind since he heard the story of Dean being raised from hell and eventually he decided to confront Cas about it. So one week, when the angel came to visit, he asked.

The warlock was hesitant. "Cas?"

"Yes Merlin?"

There was no going back now, just do it Merlin thought. "You told me how you brought Dean back from the dead- from hell- correct?"

Cas nodded as Merlin continued. "Do you think it would be possible to bring-"

"-Arthur back?" Cas finished his question for him.

Merlin nodded and Cas smiled sadly. "I've been trying to find the right time to tell you for a while but I didn't want to get your hopes up." He explained, "I'm sorry Merlin but it's just not possible."

Trying not to look disheartened, he nodded but after a painfully long pause Castiel added with a grin, "I can't bring back what's already here.

He gave his friend a moment to digest this information before continuing. "He was reborn around two decades ago. I couldn't find him but I got a start anyway- here." The angel passed him a piece of paper with two words written on them: H.C. Clements. Merlin knew the company; it was a security firm that had a branch in the nearest city to where he lived.

"What does it mean then?" he asked.

Cas shrugged, "I've no idea but it's the best lead I could find on Arthur. I'm sorry; I can't stay for long I have to be somewhere." With that the angel bid his friend goodbye and left him with that note.

A few weeks later

Merlin had decided that his best bet for finding Arthur would be to take up a job at the company Castiel had told him about so he had applied for a newly vacated position working for the newly promoted head of the branch. All he'd really have to do was run errands and follow instructions the boss gave him, but that was nothing he wasn't used to.

It was his first day at his new job and as Merlin was walking up to the office he heard a man laughing, surrounded by a crowd of people. Merlin couldn't see his face, but he could see the young temp who he was bullying.

"Hey, come on, that's enough." Merlin told this bully, whoever he was.

"What?" A man stood up from the middle of the crowd. Internally Merlin slapped himself, of course it was him. Who else could be that much of a dollop head? Despite this however, he couldn't help the overwhelming sense of joy in his heart.

"You've had your fun my friend." He remembered exactly how this went.

The man looked confused. "Do I know you?"

Holding out his hand Merlin introduced himself, "I'm Merlin."

The bully didn't take his handshake. "So I don't know you."

"No."

"Yet you called me friend?" He sounded shocked at being talked to like that. Even in this life he was just the same.

Merlin smiled to himself. "That was my mistake."

The man seemed confident he'd won. "Yes I think so."

But Merlin knew how to knock him down a notch every time. "Yeah. I'd never have a friend who could be such an ass."