"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."

"That's certainly higher than I would have guessed. Is that for your world, or this one?"

"That is for around this point in the past of my world. It's similar-looking enough that I'd be surprised if malaria played a much smaller role in your history than mine."

For just a moment, Dumbledore looks very old and very tired.

"Does your history also include people who saw the problems with the world, and set out to fix them no matter who else might object, and ended as terrible warnings for the next generation?"

"...that sort of depends on how generous you are with the term 'problems with the world'. Look, Muggles will not be able to detect my spaceship. I'll keep it under cloud cover and it's proof against all of this era's other technology. The thing they will notice about mosquitoes is... not much. There will suddenly be a lot more of them, but not of a kind that bothers humans or livestock, because only female mosquitoes do that, so only entomologists will notice. The entomologists admittedly might notice but what they will be able to report is that for awhile they caught far more males than females of specific mosquito species, and then those species went extinct. Even if some jerk decides to deliberately release currently captive mosquitoes to reseed the population those ones won't have malaria."

"Dozens of witches and wizards every year think they have a brilliant idea that will help muggles in a way they won't notice. The only reason wizardkind has stayed hidden as long as it has is because carrying out those ideas is forbidden."

"About that, uh, cameras are about to get a lot more ubiquitous and their storage of images a lot less local. If your fundamental goal here is 'don't be noticed' then even if you don't see any ethical problems with memory-charming people for receiving the occasional leaks you must have, you have an issue coming up way bigger than some confused entomologists."

"That is concerning. I have noticed the pace of Muggle technology, but the ability to transmit an image long distance before anyone can get to the camera would be . . . difficult to adapt to."

"I can imagine! Look, I'd be happy to have an entire argument about whether it is feasible for the mass use of unethical charms to keep wizardkind concealed and in total unaccountable control of their every interaction with Muggles. And whether this is desirable. Later. After I eradicate malaria."

"I am aware that I cannot stop you. I simply want to ensure that you are prepared to handle the consequences of your actions."

"You going to tell everyone it was me, have them throw me in Geneva Convention Violation: The Island?"