Two new short chapters! Since the next one is coming tomorrow and we know it'll be short, let's use one thread for both.
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 105 (and chapter 106, once it comes out tomorrow). EDIT: based on Alsadius' comment about thread creation for MOR chapters, let's also use this thread for chapter 107 (and future chapters until this nears 500 comments) unless someone objects to doing so. Given that this is the final arc we're talking about, thread titles should be updated to indicate chapters covered.
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.)
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:You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).
If there is evidence for X in MOR and/or canon then it’s fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that “Eliezer said X is true” unless you use rot13.
I just realized why some spells were causing Harry dread, apprehension, and anxiety in chapter 104. It's not because Professor Sprout is controlled by Professor Quirrell (which she is), since other spells of hers fail to trigger the effect and yet one of Tonk's spells does. It's because Quirell is using metamagic to influence the outcome of the battle! He empower's Sprout's brown bolt so that it tears through Professor Snape's shield, and he quickens her stunner so that Snape can't dodge. Then he empowers Tonk's spell to ensure that she will take out Sprout.
In retrospect, this makes perfect sense. There are too many people involved, and combat is inherently chaotic; there is simply no way Quirrell can predict exactly how the fight will go. But he can be there, using gentle nudges to actively steer it towards the small region in outcome-space that ranks high in his utility function, and hope that Harry Potter is too distracted by the battle to notice (which he was; his deduction that Quirrell is behind the plot never once mentions this fact). As a bonus, this explains how Sprout can defeat Snape, when normally we wouldn't expect her to stand a chance.
The entire point of that whole battle is to encourage Harry to commit his hidden resources (Lesath under the Cloak). The whole brawl is basically a show put on for Harry's benefit. Since Quirrell controls the time of Harry's coming to the scene, he could easily take out Snape himself and move him out of the way earlier. He didn't need to bring Sprout or manipulate others to come.
Since Quirrell neglected to ask Harry in Parseltongue whether he still has hidden resources Quirrell doesn't know about, it's still just about possible that Cedric Diggory, Time-Turned, is following them under the second Cloak. I hope he does.