Thanks a lot!
This
was a real stinker, very good indeed.
How did I work it out? After you said the answer wasn't in the Silmarillion, I guessed it would probably be LotR, and while I was going through the characters trying who might fit suddenly something went
bing! in my head. Where the high and mighty fail, the small and lowly may provide the solution... or something like that.
Now I've got to think of a new one again. I can hear
Morsul bumping already...