"You're very welcome." And they can make their vaguely unpleasant teleport back to the school.

Gosh, how vaguely unpleasant. Cam rids himself of the coat, flies up to the castle.

Hogwarts is as architecturally grand and spatially unreliable as ever.

He ensconces himself in the library some more.

He can make a sizeable dent the collection, at least the parts that cover magical history, culture, and zoology rather than practical skills he can't learn, by the time Dumbledore sends him another note. It's vaguely and cryptically worded, but in context it means that Harry has gotten pretty good at Occlumency and they're ready to try to take the bit of Riddle out of his face.

Assuming the note also contains information about when and where they should meet for this, Cam turns up.

That much at least Dumbledore is capable of putting in plain English. Harry is there too, looking nervous in a "let's get this over with" way.

"Thank you for joining us. I believe young Harry is now able to contain the fragment of Tom Riddle entirely within his scar. I hope you will be able to confirm this, and extract it safely."

"Let me check," says Cam agreeably, and he does some very fine-grained conjurations for the that-one-over-there location of Tom Riddle. Any skull or brain inclusions?

Harry shuts his eyes and concentrates, and once he's doing so the Riddlebit includes a little disk of skull but no brain.

"Okay. I'm going to anesthetize you, check again, then stick a string to your scar so I can interpolate and pull at the same time. When I replace the area do you want to keep the scar for cosmetic reasons or no?"

"It would be nice if people couldn't recognize me, but if people see it gone they'll ask all kinds of questions . . . But I think I want rid of it anyway."

"Gone it is. Do you want me to warn you or do you want it over before you know it's underway?"

"Just do it."

Anaesthetic. String. Interpolation-and-yank-and-replace.

Harry looks surprised that it genuinely didn't hurt. He runs his fingers over his newly smooth forehead, then stares at the extracted chunk. "Woah."

"Congratulations," Dumbledore tells the pair of them. "It should now be safe to collect the other pieces and destroy them all at once, so that Voldemort cannot return."

Harry nods, asks if he's done and can leave, and gets an affirmative.

"Do you need me on that? I was just about done determining that wizards do not have a strong effect on whether the malarial mosquito deserves to exist."

"Your help would speed up the process immensely, but I believe I can make good use of what I already know. What exactly are you planning to do regarding malarial mosquitoes?"

"Drive 'em extinct."

"That sounds like quite the endeavour. Are the muggles likely to notice?"

"They will certainly notice that no one is infected with malaria. They may or may not notice the initial steps."

"I strongly recommend caution. Your magic is different from ours, but any inexplicable event could get muggles looking closely at things it would be better if they did not."

"Professor, do you know the high-end estimate for how many human beings have died of malaria?"

"I do not."

"Half of them."