Years Earlier

They tell me he is special—different from other boys his age.

Naturally, that doesn't mean much to me. After all, Mum had gone on for months about how "different" I was when I was his age. But the doctor knew what my diagnosis was back then: a boy who thinks he knows too much. (He was only slightly wrong, however. I do know too much.)

But this time it truly is different. He has no idea how to deal with Sherlock's brain.

I hear them discussing it in the room next over, they leave the door open just a crack. Mum is doing that loud whisper of hers, like she thinks no one else can hear her. The doctor replies in a low voice and I lean closer to listen.

Autistic, he supposes. High-functioning. Perhaps Asperger's. Mum isn't quite sure what that means, and she gasps.

Will he be all right? What can we do to cure it?

I can't be bothered to listen to their conversation anymore—especially when I know they're both wrong on so many accounts. There's so much more to my brother than that.

I catch a glimpse of myself in the small mirror on the doctor's desk. I'm tired. The part in my hair has gone askew, so I quickly fix it. I'm still not so sure why Mum insists that we dress so smart when we visit the doctor's office. Out of the corner of my eye, I see Sherlock kicking his legs against the legs of the chair he's been sitting in for the last hour. I straighten my back, trying to set a good example.

"Mind your shoes, Sherlock," I say. "You'll scuff them if you keep that up."

Sherlock's legs stop moving for a few moments, but when his gaze returns to the vast shelves of books in the office, he continues. He must be bored. I know it when I see his tiny body slouch against the back of the chair.

"Mycroft," Sherlock drawls. "How much longer?"

"Can't be sure."

"I'm bored."

I smirk. He sounds positively drained. "No reason to lounge about like that," I mention as I wave a hand in his direction. He understands, and he sits up straight again. His grey eyes scan the room once more, and it is now I discover that he's actually looking for something. I try to ignore it at first, only to see if I can find what he's looking for. But when he jumps out of his seat and examines the walls, I raise my eyebrows at him, trying to impersonate Mum's best chastising face.

It doesn't work. I sigh audibly.

"What are you doing, Sherlock?" I have to ask.

"I'm looking for where the doctor keeps his dog," the boy replies nonchalantly. My eyebrows crease and I let his words hang in the air for a moment. His dog? Why on Earth would a doctor keep a dog in the office? And how is Sherlock so certain that this man even owns one? Despite how strange it sounds, my brother continues to probe the walls, no doubt looking for some sort of secret dog compartment.

"His dog?" I ask. But now I'm curious. This is a better test than any of the ones that the doctor had conducted—all about tests, and numbers, and personality. No, this is far better. This way I can see into my brother's brain and see what makes him think. Perhaps even see if he thinks like I do. "Why would he have one in his office?"

Sherlock points to the curtains briefly, barely even looking at them. "He tied the curtains up," he says simply. "Rather well. Probably to keep them away from the dog."

"What about a cat?" I challenge, though I already know that's impossible. "Cats are a bigger threat to curtains than a dog would be, don't you think?" Sherlock says exactly what's on my mind in response.

"But cats can jump higher than a small dog," Sherlock mentions quickly, almost in frustration. He turns to the cabinet in the corner and nods his head at it. "And he didn't do anything about his fish. If he was concerned enough to tie up the curtains to keep a cat away, he should've covered the fish."

He continues to search the room, but he stops as he approaches the tall lamp.

"Look," he gushes. "He even tied up the cords here."

"So this 'dog' could also be a baby," I wonder aloud. Sherlock grimaces at the word. Sounds as plausible as the dog.

"I hope it isn't," he murmurs in disgust.

"The doctor did mention his wife. Perhaps they have a newborn."

"Babies don't meddle with curtains," Sherlock nearly spits. True enough, I think. They meddle with everything else.

After we spend more time deducing, we come to a conclusion. Somewhere in the office, the doctor keeps a small toy dog—long-haired and young. We also know that he doesn't trust it, or perhaps he doesn't even like it. I insist that it belongs to the wife, but Sherlock isn't so sure. At last, Mum and the doctor return after their long discussion in the other room. Mum puts Sherlock's coat on him and pats his cheek. He doesn't react.

"Ready to go, darlings?" she asks. I nod, but Sherlock doesn't. His entire demeanor has changed now that the doctor has entered the room again. He's reserved, guarded, and very inquisitive.

"I want to see the doctor's dog," he deadpans.

The doctor raises his eyebrows. "But I don't have a dog," he says simply.

I gauge Sherlock's reaction, but there isn't one on his face. I'm sure he's absolutely roiling on the inside, but I'll have to ask him later. However, the doctor doesn't stop there. He smiles, obviously in an attempt to get Sherlock to do the same.

"But, my next patient has a dog," he chuckles as he adjusts his glasses. "Nasty little bugger, that one. Yorkshire terrier. Always seems to get his legs tangled in everything."

I exchange brief glances with Sherlock, who looks amused with himself—a mix between pride and excitement. I'm glad that the entire endeavor pulled him out of his boredom.

Now, we call this our "deducing game."