McGonagall's wording ("trapped outside Time") suggested to me that she knows at least the basics of where Dumbledore went. There can't be too many spells or artifacts capable of doing that, or Dumbledore wouldn't have had to resort to an Atlantean relic in the first place.
I wonder if Dumbledore briefed her on the trap.
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 118.
Plans for next chapter release:
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.)