Chapter 54: why don't Harry and Quirrell cast Somnium on Bellatrix instead of deceiving her? (The deception requires Quirrell to tell Harry the Death Eater password, among other things...) Why does Quirrell talk to Bahry so confidently while Bellatrix can hear him? Why does he follow his whims to play-duel and then kill Bahry instead of quickly subduing and memory-charming him, if they planned to pull off the perfect crime? Why is he so vulnerable to Dementors that he drops immediately when Harry's Patronus vanishes, even though Bahry's Patronus is still there successfully protecting Bahry and Harry? (Or am I misunderstanding the reason for his screaming? It's very similar to Harry's screaming when he first encountered a Dementor. If the screaming were caused by Quirrell's spell coming in contact with Harry's - brother wands or whatever - then Harry should've felt a symmetrical effect, which he didn't.)
Also, am I the only one stupid enough to only now realize that the professor's name is Quivering Squirrel?
Why does he follow his whims to play-duel and then kill Bahry instead of quickly subduing and memory-charming him,
Presumably, as I mentioned below, for the stated reason that "'It's been quite a while since I had a serious fight with a serious opponent'" As Quirrel himself said earlier, if you can't have some fun once in a while, what's the point?
[Update: and now there's a fifth discussion thread, which you should probably use in preference to this one. Later update: and a sixth -- in the discussion section, which is where these threads are living for now on. Also: tag for HP threads in the main section, and tag for HP threads in the discussion section.]
The third discussion thread is above 500 comments now, just like the others, so it's time for a new one. Predecessors: one, two, three. For anyone who's been on Mars and doesn't know what this is about: it's Eliezer's remarkable Harry Potter fanfic.
Spoiler warning and helpful suggestion (copied from those in the earlier threads):
Spoiler Warning: this thread contains unrot13'd spoilers for Harry Potter and the Methods of Rationality up to the current chapter and for the original Harry Potter series. Please continue to use rot13 for spoilers to other works of fiction, or if you have insider knowledge of future chapters of Harry Potter and the Methods of Rationality.
A suggestion: mention at the top of your comment which chapter you're commenting on, or what chapter you're up to, so that people can understand the context of your comment even after more chapters have been posted. This can also help people avoid reading spoilers for a new chapter before they realize that there is a new chapter.