A/N: This is my first Fanfiction, so please be ice. I'm really nervous and quite self-conscious about my writing, so if you have anything nice to say, please do. I don't have a plan really laid out for this, so suggestions for future chapters or events would be much appreciated!

Disclaimer: I do not own Merlin or Sherlock.

They entered the flat and were both surprised to find that someone was already there. Sherlock froze in place as he stared at the man sitting in his chair. He was young, very early twenties. He had short black hair, and bright blue eyes that were sparkling with amusement. His sharp cheekbones and angled face made him the spitting image of Sherlock. But who was he?

John looked to Sherlock and saw him reach up and start rubbing his head, as if he had a headache.

"Hello Sherlock," The man in the chair said cheerfully. "Long time no see."

Sherlock kept on rubbing his head. "What do you want Merlin?" He asked tiredly.

"Geez Sherlock, no need to get touchy, and you should really stop rubbing your head like that, it will only make it worse."

Sherlock immediately took his hands off his head, glaring at them as if they had offended him in some way.

"I'm sorry, but who are you? And how did you get in here?" John asked, confused.

Sherlock sighed tiredly. "John, meet my little brother Merlin."

John's eyes practically bulged out of his head. "There's another one!?" He asked loudly, turning to Sherlock. "How many siblings do you actually have!? Is there any more family of yours I should be looking out for?"

Sherlock glared at him before turning sharply and walking into the kitchen.

"Don't mind him," Merlin said, directing his attention back to the living room, "He gets like this anytime I come around." Merlin stood up, walked over to John, and offered his hand out to shake. "It's nice to meet you." He said with an amused smile on his face.

John shook his hand, still trying to process how this smiling man could even be related to Sherlock. "I don't know he seems pretty normal to me." John said to Merlin as he looked at Sherlock who was, again, rubbing his head and pointedly not looking at Merlin.

Merlin saw this as well and rolled his eyes. "No, trust me; he's more than annoyed right now. I give him a headache."

John looked confused at this. "Why would you give him a headache, you've barely spoken to him since we got here."

Sherlock looked up at them again, and took a deep breath before walking back over to where they were standing. "What are you doing here Merlin?" He asked again.

Merlin sighed and ran a hand through his hair. "I just need a place to lie low for a while. Someone came pretty close to finding out two days ago; they might still suspect something so I need to hide for about a week or so."

Sherlock's eyes widened and John was surprised to find out that he almost looked worried. "How close were they to finding out? What did you do? Why don't you just go to Mycroft?" The last bit was said with an almost whiny quality to it.

Merlin was starting to look a little annoyed. "They were close, but not dangerously so, I don't need a change of identity or anything. I didn't do anything out of the ordinary; I was just in the wrong place at the wrong time. And I came here instead of Mycroft's because I wanted to see you."

"But why do you have to stay here?" Sherlock almost whined.

"Because I trust you and it's safer here."

"What about staying with one of your little friends?"

"I can't stay at Arthur's because he is still on his honeymoon with Gwen. Gwain is vacationing in India. Everyone else isn't as trustworthy as you are."

Sherlock glared at him again and walked to his room, slamming the door without another word.

Merlin threw up his hands in frustration and walked back over to the chairs, falling into Sherlock's with a huff.

John, still not sure what to make of this conversation slowly followed Merlin and sat across from him.

"He'll let me stay; it will just take a bit for him to accept it." John was startled by when Merlin spoke suddenly.

"Why's he so agitated?" John asked curiously.

"Because he can't read me, and it frustrates him to no end." Merlin replied with an amused smirk on his face.

"What do you mean he can't 'read' you?"

"You know him, the great detective that can take one look at you and know all your secrets. Well he can't do that with me. Mycroft either."

John's eyes widened. "Seriously?" he asked not sure if such a thing were possible.

Merlin's smirk grew, "Yep, well, it's not quite that he can't read me, it's just that he can't trust what he reads." His face grew thoughtful, "Think of it this way; if someone was trying to read your mind for something you didn't want them to know, which would be easier: trying to wipe your mind of all thought, or just thinking of something else?"

"Well, I suppose it would be easier to just think of something else." John replied, slightly confused.

"Correct," Merlin smiled widely, "My brothers can't read me, not because there's nothing to read, but because I'm giving them something to read that isn't true. Sherlock knows this, and it gives him a headache trying to reconcile what he's seeing with what he knows may or may not be true."

John wasn't quite sure what to think of this. The only other person Sherlock hadn't been able to read was the Woman… and she was naked at the time. Well, Merlin thankfully wasn't naked, and according to Sherlock it was impossible not to give something away. He was just about to ask Merlin about this when Sherlock came out of his room.

A/N: Let me know if you want more!

Update: 12/25/15 - minor grammar/spelling changes.