Yhea, that's not a workable approach. Seriously, Flamel is centuries old and has had the key to eternal life for all of that. and the largest hoard of lore on the planet for most of it. Trying to legilimency that mind has the most likely result of you becoming a drooling vegetable.
The relevant section (Ch 108):
Next you will ask why I did not kidnap, torture, and kill Perenelle after I learned the truth."
This had not in fact been a question that had come into Harry's mind.
Professor Quirrell continued to speak. "The answer is that Perenelle had foreseen and forestalled the ambitions of Dark Wizards like myself. 'Nicholas Flamel' publicly took Unbreakable Vows not to be coerced by any means into relinquishing his Stone - to guard immortality from the covetous, he claimed, as if that were a public service. I was afraid the Stone would be lost forever, if Perenelle died without saying where it was hidden, and her Vow prevented attempts at torture.
Perenelle's safety relied on the Stone's uniqueness and hiddenness, which is no longer a factor as far as Quirrell is concerned.
I did not attack her directly, for I was not sure of my great creation; it was not impossible that I would someday need to go begging to her for a dollop of reversed age.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 116.
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)