Sherlock Holmes, private detective, was without a clue. This was a place in which he rarely, if ever, found himself, and he most definitely didn't like it. What made it all the more infuriating was that it wasn't even about a case. It was about John Watson. More specifically, about what he'd said that evening at dinner: that Sherlock was his brother.

At first it hadn't made sense to the detective, but then the doctor had explained his reasoning, which could be summed up as basically saying that although Sherlock got on his nerves sometimes, John loved doing things with him, and would die for him if the need ever came up. Apparently, these things combined made him John's brother. And after saying all this, after pouring out his heart and showing it to Sherlock, he just went back to ordering dinner, as if he did that sort of thing every day! And then he didn't seem to expect any changes in their relationship, even after this incredible revelation. John had eaten normally, read the newspaper when they got home, had a cup of tea, and gone to bed several hours ago, all the while appearing not to notice that Sherlock was still in a moderate state of shock at hearing all this. It was incomprehensible, and yet one of the things he liked best about his flatmate. It also left the detective plenty of time to think about what to do with it.

Sherlock sat curled up on the sofa, looking vacantly at the ceiling, turning over the data in his mind. This thing, this thought of John's about Sherlock being that important to him, was exhilarating...and at the same time terrifying. Especially the last part. Because if John were ever to die for him, then where would that leave Sherlock? Not only without a flatmate, but also without the one person who not only could stand to be in his presence for longer than five minutes at a time, but who actually seemed to like him, and admired his deductions. That was far more than Not Good. In fact, he would go so far as to call it Unbelievably, Indescribably Bad.

His brain tried to consider the possibility of John dying to save him, and no longer being around-and automatically rejected the thought.

Does not compute. Data is stupid. Think of different possibility.

Instead, he tried to consider himself dying to save John. That was somewhat more palatable. At least the doctor would still be alive if that happened. But without being too swollen-headed about it, Sherlock knew John would be miserable without him; that also fit under the category of Unbelievably, Indescribably Bad.

John needed Sherlock. Sherlock needed John. They were two halves of the same equation; separated, they were incomplete. Anything else did not compute. So it would just be best for everyone if neither of them ever had to die to save the other. Of course, he knew it was impractical to think that they would live forever; nobody did that. But they could at least try to keep each other alive for as long as humanly possible. Yes, that seemed to be the best solution: John and Sherlock must stay alive, and stay together. Because, as John had somehow realized before him, they were brothers. Brothers that cared about and supported each other in ways that some people couldn't begin to understand (cough, *Mycroft*, cough). He burrowed into the sofa with a happy sigh, glad that this problem had been cleared up. Sort of. There was an odd feeling in his chest that he should find some way to show John that he appreciated his feelings, and felt the same way.

The next day, he was awakened by the sound of John making tea in the kitchen. Breakfast proceeded normally, and he didn't have to spend too much time being bored before a new client showed up. It was a man, mid-forties, former chain smoker, worked in an antiques shop, divorced with at least two children and three grandchildren, worried about possibly having lung cancer, not overly clever, possibly because he was also dyslexic. He came up the stairs, and immediately started talking about how someone had broken into his shop late at night, and ignored the fancy gold watches, the small works of art, and the china ornaments to steal a pair of rather old leather shoes. Sherlock couldn't help being interested, and removed his bathrobe to put on his coat and scarf instead. As he was doing this, John came out of the bathroom, where he'd been shaving.

The client, Mr. Something-or-other, looked over at him in surprise. "Who are you?"

Had this man not read the blog that everyone in London was so fond of, or the newspapers? Weirdo. The detective didn't think twice before answering, "This is my brother, John."

John's head jerked sharply in his direction, eyebrows rising up into his hairline. Then, just as quickly, his face relaxed into a very warm, soft smile, and he nodded slightly. The odd feeling in Sherlock's chest went away in a heartbeat.

The shopkeeper looked back and forth between them, bemused at their differences in physical appearance.
"Well, between you and me, I think he's adopted." The doctor swiveled his head towards Sherlock, who gave a partly-fake irritable snort.

"Really, John, a comparison of our respective facial features with those of Mummy, Father and Mycroft shows that obviously you're the adopted one."

And they set off for the antique shop, still good-naturedly bickering.