I remember it clear as yesterday. Harry and Holmes were discussing a case, picking apart a client's motivations and insecurities over breakfast. The meal itself was a simple affair, consisting of scone and eggs. When an old friend saw fit to visit, such simplicity was soon put to rest.

-Excerpt from A Study in Magic, by John Watson, MD

-oOo-

Harry waited by the door, impatiently bouncing on the balls of his feet. Adults, he thought, did well enough once an adventure got started, but were absolutely no good at getting them rolling.

For the past thirty minutes, Watson had been interrogating Professor McGonagall about the minutest aspects of Harry's schooling. How was transport arranged? What were meals like? Did they put emphasis on proper nutrition?

Holmes, detached as ever, sat near the window, smoking a clay pipe. The detective observed Watson with concealed amusement, clearly evident from his bottom lip pulling three millimeters to the left.

Harry decided the starting of his newest adventure would take a proactive approach. "Uncle, aren't you running late? Don't you have to see your patient in the country?"

The doctor paused his barrage of inquiries long enough to glance at the clock. "Great Scott! I'm late! Holmes, Harry, Minerva."

Watson pumped McGonagall's hand once and rushed to the door. He swept up his cane and hat from a small table, and paused only long enough to remind Harry to write before leaving. The remaining occupants heard him clatter down the stairs, followed by the distant sound of the front door slamming.

In the silence, Holmes chuckled quietly. "Excellent, Harry. Now explain."

Harry beamed, and McGonagall looked at them both, puzzled.

"Easy," Harry replied, "He always uses his heavy black cane when he goes out to the country, and he put his hat on the table instead of the hat rack, so he was planning on leaving soon. He lost track of time when the Professor showed up."

"And?" said Holmes.

"And his doctor's bag was open when I woke up this morning, so he either checked it this morning or last night. He only checks his bag when he has a patient to see."

"And?"

Harry narrowed his eyes at the detective. "And that's it."

Holmes took the time to stretch luxuriously before standing. "Wrong."

It was a single word, but to Professor McGonagall, it seemed like Harry had been physically struck.

"Or perhaps," continued Holmes, "I should say, not enough. Your observations are quite refined, but you leap too far in your deductions. The only real evidence you possess of Watson's country patient was the cane. The other observations lend strength to your hypothesis, but only if your deduction with the cane is correct." Sherlock shrugged, refilling his pipe with tobacco. "Watson could have just as easily mislaid his other cane, and employed the black one as a substitute."

Harry was wilting before McGonagall's eyes, and the conversation was leaving her completely bewildered.

"Yes," said Holmes, "Watson is going to the country today. I know this because of a crucial piece piece of evidence; one you've failed to ascertain."

Holmes paused dramatically, and sat in a chair by the mantelpiece. "His shoes. Crusted around the soles of the footwear he wore yesterday, I perceived a fine, red dust. Brick dust, to be precise. The same kind of brick dust one would find in ample supply at a demolition site. A demolition site which can be currently located right next doorto our local train ticket office. Watson, being the prudent man he is, naturally prefers to purchase his train tickets well in advance."

Holmes raised a single finger to his head. "And thus, a string of mere coincidences becomes something more; an irrefutable series of observations that lead us to the logical conclusion."

Holmes crossed his fingers and stared into the fireplace. "Remember Harry, guessing is the greatest enemy to reason. It is utterly destructive to the logical faculty."

Harry was standing stiffly, ram-rod straight. He nodded. "I understand."

"I know. Good day, Professor McGonagall."

The professor blinked. Surely, she thought, that's not all? He's not just going to-

But Harry was already tapping her arm. "Can we go now?" he asked.

She spared a single glance to Holmes before nodding. "Of course, Mr. Potter. We've a long day ahead."

The pair had just stepped into the hallway when Holmes called out.

"Harry?"

Harry and McGonagall turned, the latter struck with what she saw. The professor thought Holmes was an awfully lonely looking man, sitting alone in his darkened sitting room.

Holmes shifted, an strange, uncomfortable gesture, Harry noted. "In the art of detection," said Holmes, "It's of the highest importance to be able to recognize, out of any number of facts, those which are incidental and those which are vital. If one cannot recognize these crucial points, one's attention and energy spreads hopelessly thin."

Harry and McGonagall waited, but Holmes turned away and lapsed into silence.

-oOo-

Walking down the stairs with The Boy Who Lived, Professor McGonagall felt a pressure lift from her chest. Sherlock Holmes. A great man, surely, and yet...

She looked down at the young boy beside her, and thought of the cold man left behind, sitting alone before a dying fire. The way he had tested Harry had clearly been a stressful ordeal for the boy. Not for the first time, she questioned the wisdom in placing Harry with such a man.

"You don't trust him, do you?"

Mcgonagall looked down. Harry was looking at her with an open, unguarded expression. The face of a child, she thought. And yet, something seemed off. She had the fleeting impression of very old eyes, somehow stuck into a little boy's face.

"He's a brilliant man." she answered.

"But you don't like him."

"Mr. Potter-"

"It's alright. I didn't like him very much either, in the beginning."

"...And now?"

"Now he's my dad."

McGonagall felt something twist inside her chest. She had personally known James and Lilly Potter. Harry never even knew his parents, and now all he had was that, that machine of a man. Thank goodness for Doctor Watson. He seemed a smart, practical person, but alas, he appeared to spend more time at work than home.

"He taught me how to think," said Harry.

McGonagall turned away from her thoughts, and looked again to Harry. "I see. Is that what that game was about, before we left?"

An expression flashed across Harry's face, too fast for her to read. "It's not a game. Observation is the cornerstone of detection."

"Is that what he's been teaching you? To be a detective?" McGonagall frowned. She didn't think much of detectives in general. The investigative Auror teams during the war had been useless. Perhaps even worse than useless. Then again, Sherlock Holmes wasn't an official detective. He certainly wasn't connected with the police. If anything, they seemed to look down on him.

"Will I have to use a wand all the time, too?" Harry asked.

McGonagall's thoughts scattered. "What was that?"

"A wand. Will I have to use one all the time, like you, or is that an optional thing?"

"Wands are conductors of magic. Everyone has one."

Harry continued walking, and carefully posed his next question. "So wizards need wands to use magic?"

"Almost always. Some forms of wandless magic can be used for simple tasks, but it tends to be rather imprecise."

"Oh."

McGonagall smiled to herself. Such curiosity. Harry would fit right in at...

She paused, frowned, and turned to Harry. "And who told you about wands?"

"Well, it is holstered right there, professor," said Harry, pointing to her leather wand holder.

McGonagall's hand brushed the holster in reflex. "I'm aware. But how did you know wizards, and I quote, 'use them all the time'?"

Harry craned his neck, still observing her wand holster, taking the intricate designs empbossed in the leather. "Everyone seems to think being small is such a bad thing. No one thinks it's good for much, but you'd be surprised. Take right now. It lets me have a good look at your hands. You'd be surprised what a person's hands can say about them."

McGonagall looked rather dubious, and Harry continued.

"One time, my dad worked a case where the client was a professional writer. This guy hated typewriters. He only worked with pencil and paper. That guy had very distinct callous and indentions on his palm and fingers. Almost just like yours."

McGonagall frowned and examined her hands. They looked the same as they always did. Harry happily rambled on. "Your hands tell the story of heavy use, not from a pencil, but something thicker and rougher. Your wand is a perfect match, and the logical candidate."

McGonagall looked at her wand hand again, peering closer. There, on the tip of her index finger, was the slightest of indentations. Pulling out her wand, she assumed her natural grip, almost an instinctual action after decades of use. The thin piece of wood snuggled into her hand, resting neatly on the tip of her index finger.

She glanced down, and Harry grinned up at her.

"Do you still think it's a game, Professor?"