[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.
I have a question about chapter 49 and was wondering if anyone else had a similar reaction. Assuming Quirrell is not lying/wrong, and Voldemort did kill Slytherin's Monster, then my first thought was how unlikely that Slytherin's Monster should have even survived long enough to make it to 1943. No prior Heir of Slytherin had had the same idea? Perhaps no prior Heir of Slytherin had been strong enough to defeat Slytherin's Monster? No prior Heir had been ruthless enough?
Maybe this constitutes weak evidence for the theory that Quirrell is lying.
It also could be that the Basillisk has some sort of genetic memory (or DNA-based cognition ala the Super Happies!) such that the monster in the book is not the original monster but rather a great-great grandwhelp of the original monster. This would allow any heirs to kill their specific monster while the line (and thus memories) are preserved.
(This is of course all predicated on Slytherin realizing that his descendents may be nasty enough to keep knowledge from others by any means possible).