The Hogwarts Express has a lot of compartments. It has to take about 400 students back and forth between Scotland and London every year; that means a long train. This particular compartment contains a boy, looking like someone took a normal eleven-year-old and put a Stretching Jinx on his spine, staring out the window and twisting his long black wand in his fingers. He looks painfully bored.
(Tintin is pleased not to have had to intervene. He's not entirely sure how he would have intervened, but it would probably have involved shouting, and Tintin doesn't like shouting.)
"I should get to fixing the nerve damage before that sets in, though. Can I Body-Bind you from the neck down for this, it's easier that way."
"- okay, sure," he says, sounding more curious than wary.
She flicks her wand at him, and suddenly he's paralyzed - he can move his eyes and lips, but nothing else.
Also, everything tingles. It's like his entire body fell asleep like a folded leg, and a gentle, even weight is being put on every part of his skin - at least, below the neck.
The healer starts weaving her wand through the air some more, this time more purposefully.
...he starts giggling. "Tickles," he explains to Deborah's raised eyebrow.
"Well, that's good to know."
The wandwork continues for a good several minutes, and the tingling feeling intensifies in some areas and weakens in others according to some obscure pattern, until eventually she flicks her wand again and he regains the ability to move. "Alright, the rest of it'll be potions. I'll be sending the elves with a vial every day at breakfast for two weeks, and if you don't drink it I'll find you and pour it down your throat myself, understand?"
"And- you, tiny boy. Who're you?"
"...my name is Tintin?"
"I want to give you a checkup, you're too tiny for my comfort. You others can go if you don't want to stick around."
"I wanna stick around. ...um, he might be tiny because he was born a girl?"
"I'd expect him to be taller for that. Girls grow earlier, as a rule. Come on, don't be shy."
"I am not being shy!"
Tintin approaches hesitantly.
Wandwork wandwork wandwork -
"Malnourished," the healer diagnoses. "I'm sending you potions as well. Unlike almost any other potion you care to name, these ones taste nice. Drink them. You can all leave now."
"Thank you, ma'am!" James says brightly.
"Thank you very much," echoes Deborah before starting to shoo the other boys away. They've wasted enough of their precious sleep before their first day.
"Well, that was an experience," Tintin opines.
"It was fun! And I get to keep my cool lightning scars!!!"
Deborah scrunches her nose up but does not deign to comment.
"You do! And I will be less malnourished, and possibly less tiny, though I have my doubts."
"If nothing else we'll grow to grownup height, although you may stay a small grownup."
"Being a large grownup would be very strange and I would not like it."
"Even small grownups are bigger than you though."
"Just so long as I am small enough to be underestimated."
"Ooh that's a good thought. I want to be big though."