Once all the young witches and wizards had taken their seats, the Hogwarts Express officially began its journey. Outside the windows, the scenery on both sides started to blur as the train picked up speed.
By now, Harry and Ron were far less awkward than they had been when they first met.
Harry, in particular, found himself genuinely intrigued by Ron's family—and was pleasantly surprised to learn Ron was just as curious about his. Their conversation quickly became animated as they took turns asking and answering questions, growing closer by the minute.
Sherlock, however, didn't join in.
For him, merely listening to their exchange was more than enough to piece together a great deal about the two of them.
What caught his interest more was the lightning-shaped scar on Harry's forehead.
Of course, in Sherlock's eyes, the shape looked less like a bolt of lightning and more like a capital "N."
Meanwhile, Ron, clearly energized by their discussion, suddenly decided to show off a bit of magic to impress his two Muggle-born friends.
"George taught me a spell. Said I could use it to turn him yellow."
"Him" referred to Ron's pet rat, Scabbers—a shabby grey thing that had once belonged to his older brother Percy, who was now a prefect.
Ron rummaged through his trunk as he spoke.
It was a chaotic mess. He pushed aside a pile of books, pulled out a couple of robes, and finally—after some struggle, managed to dig out his wand.
"Wanna see?"
He looked at Harry and Sherlock with barely contained excitement.
"Hurry up!" Harry urged.
Sherlock, too, looked on with interest.
During the summer, he'd already tried out several spells in most of which had succeeded—so he had a decent sense of his magical aptitude. Transfiguration, on the other hand—like turning a teacup into a squirrel, the way Professor McGonagall had—was completely beyond him.
Of course, after glancing through their textbooks, Sherlock had realized that sort of spell was well beyond first-year level. It wasn't even on the syllabus.
Clearing his throat under the watchful eyes of his friends, Ron gave his wand a flourish.
"Sunshine, daisies, butter mellow,
turn this stupid, fat rat yellow!"
One second. Two. Three.
Scabbers remained stubbornly grey and fast asleep, entirely unaffected.
Harry: (°ー°〃)
Sherlock: ←_←
Ron blinked, lifted his wand again, and gave it another try.
"Sunshine, daisies, butter mellow,
turn this stupid, fat rat yellow!"
Still nothing.
Harry: (lll￢ω￢)
Sherlock: ←_←
"…Yeah, figured this spell was rubbish," Ron muttered as he stowed away his wand, disappointment written all over his face. "Bet George knew it wouldn't work."
"Is it the wand's fault?" Sherlock asked casually.
Ron looked confused. "Huh?"
"Your second brother's wand," Sherlock said, nodding toward it.
The wand was clearly old and worn, with chipped wood and a faint white glimmer at the tip.
"Oh—yeah, that used to be Charlie's. It's so battered the unicorn hair's practically sticking out. But Dad says it should still work…"
Ron ran his fingers fondly along the wand's faded grain, then suddenly froze. "Wait a second—how did you know this was my second brother's wand?!"
"Ron, even I can tell that's a secondhand wand," Harry cut in, unable to resist.
There was a hint of satisfaction in his voice—like he'd just scored a small intellectual victory.
"No, no—what I mean is, how did you know it was my second brother's wand?" Ron protested. "I never even told you how many brothers I have!"
Good point.
It only now dawned on Harry as well.
Sure, it was easy to tell Ron's wand was old. But Sherlock hadn't just said it was secondhand—he'd said exactly which brother it had belonged to.
That was downright uncanny.
Sherlock just smiled.
"Not only do I know it was your second brother's wand—I also know there are seven children in your family.
"You're currently wearing your eldest brother's robes, using your second brother's wand, and you've got your third brother's pet rat. Your fourth and fifth brothers are twins, and you have a younger sister who hasn't started school yet."
Harry and Ron stared at him, utterly gobsmacked.
For a long moment, neither could get a word out. Finally, Ron's face turned red as he grumbled, "Sherlock, that's not funny. You clearly looked all this up beforehand!"
Harry jumped in to back him up. "Yeah, you must've known about Ron's family already—there's no way you could've guessed all that."
In perfect solidarity, they declared: Sherlock must have done some prior research.
Sherlock was entirely unfazed.
"My dear Harry, making these deductions was really quite simple. All it takes is keen observation and logical analysis. You could do the same."
"Think back to what I said about you earlier. Once I walk you through my reasoning, you'll both say, 'Oh! That's all it was?'"
Harry looked doubtful. "Really?"
"I don't buy it," Ron said, shaking his head vigorously. "You definitely did your homework on me."
Compared to Ron, Harry was more open-minded—he had seen Sherlock pull something similar before. Still, the level of detail here went well beyond the previous demonstration.
Seeing the curiosity in their eyes, Sherlock chuckled.
"All right, I'll explain:
"Ron's robes, wand, books—even his suitcase—they're all secondhand. That tells me he comes from a large family. Sorry, I peeked while you were digging through your trunk earlier.
"Your robes have been altered and don't quite fit. Once you change into them later, I bet your sneakers will stick out underneath. The wand's obviously old—even Harry spotted that."
Harry: |(*′口`)
"But that still doesn't mean it's from my second brother!" Ron blurted out.
Sherlock shrugged. "Usually, wands and robes are bought together. But your robe is clearly older than your wand, which suggests they came from different people.
"And things like wands and robes only get passed down once someone's graduated—so your older brothers must already be out of school.
"Then, when you tried to perform that spell, you mentioned that your prefect brother gave you Scabbers, and that the incantation was something George taught you. That means you have at least two more brothers.
"And just my luck—I saw you chatting with a pair of red-haired twins on the train earlier. No one would doubt you're related—same hair, similar faces.
"But they're not prefects. The prefects ride up front, in two special compartments. That's common knowledge.
"So, based on all that, it's not hard to work out: you have five older brothers. Your robe and wand came from your eldest and second eldest, your rat from your third brother, and the twins make four and five."
"…But how'd you know I have a sister?" Ron pressed.
"You probably didn't notice, but there were a few long red hairs clinging to your shoulder. Judging from the length and texture, the owner is close to your age—meaning a sibling. Likely a sister.
"That's the only detail I guessed, rather than deduced. But I'd wager I'm right—she hasn't started school yet, has she?"