[Voralphion]

I think it might refer to Gandalf and his fight with the balrog


Hopes are shattered, ( the balrog appears)
Dreams awaken,
The old three cornered hat is taken. ( No idea)
Things expected broke asunder, (Gandalf's staff "broke asunder" as he broke the Bridge of Khazad-Dum)
As they fell completely under. (Gandalf and the balrog fell together under Moria to the roots of the earth)
Out of thought and the depths of time, (when he died he said he passed out of time)
Returning then, sweetly sublime. ( he returned from the dead)