I have the feeling I should be able to find that with the clues given so far, but that would involve time and effort!
So to make it easier for myself - and probably for someone else who'll then get it first - I'll ask for another letter: R, please.
__________________
'Mercy!' cried Gandalf. 'If the giving of information is to be the cure of your inquisitiveness, I shall spend all the rest of my days in answering you. What more do you want to know?' 'The whole history of Middle-earth..
.'