McGonagall's lips twitch when she's stifling a smile (this is stated several times in the text). Perhaps the same is true of Quirrell? In the second case, canon!Quirrell is responsible for both trolls that occur in the first book and at least according to Harry Potter Wikia is supposed to have a talent for using trolls. In the first case... I think what happened when Voldemort killed Harry's parents involved a sacrificial ritual (Lily sacrificing her life for Harry), so Quirrell might have found that particular idea ironic. Or maybe he's just amused by the idea of Harry using sacrificial rituals because of previous events.
Also Dumbledore:
"I recognize the name, Harry," said Dumbledore. The old wizard's lips twitched upward. "Although honesty compels me to say that dear Winston was never one for pangs of conscience, even after a dozen shots of Firewhiskey."
No old uses for Quirrel aside from this:
The Defense Professor's shoulders twitched in a slight shrug, the only movement they'd shown since the battle ended.
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 90. The previous thread has passed 750 comments.
There is now 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.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18,19.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: