Mcgonagal would have to have someone else transfigure her, or else the spell would end when she dies. (Perhaps dumbledore? Not sure he would go for it.) Polyjuice would be another approach, but it wears off after an hour, so dumbledore would have to do another body swap after Hermione/mcgonagal is killed. Again, not sure he would go for it. Who else? Quirrel might be desperate enough. Snape is loose but I don't see him going for it.
So several things would have to fall into place but the plot buildup is definitely there.
Wasn't there a story about someone who accidentally Polyjuiced herself into a cat and, instead of getting help, hid from the teachers, so she got stuck cat-like? McGonagall could turn into a cat and Polyjuice herself into Hermione from that state, to get the effect deliberately. The waxy, doll-like appearance could be a side-effect of deliberately botched Polyjuice. Or... Hermione could Transfigure McGonagall. Hard, but quite possibly just within her capabilities, with guidance.
The ward message is a problem, but, as jaibot suggested, maybe McGonagall enrol...
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 chapters 91 & 92 . The previous thread has passed 500 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, 17,18,19,20.
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: