I thought that the strange word that echoed through Harry's mind could be somehow related to this completely mysterious fragment of text found at the beginning of chapter 1:
Beneath the moonlight glints a tiny fragment of silver, a fraction of a line...
(black robes, falling)
...blood spills out in liters, and someone screams a word.
Not that I think this would explain anything.
Update: This post has also been superseded - new comments belong in the latest thread.
The second thread has now also exceeded 500 comments, so after 42 chapters of MoR it's time for a new thread.
From the first thread: