Thanks to Brendan for a Prize which I found extremely difficult.
FOI 1. LOI was 21, which took about a third of the total solving time to figure out!
COD 3 over 21, 12, 7 and 13.
Perhaps I'm just tired on a Friday evening (US) but quite a few clues were highly challenging IMO.
I didn't notice a theme (so what else is new?), but [SPOILER ALERT] I believe the puzzle is a pangram, so if you're stuck it might help to think of answers containing unusual letters. ;-)
Going to take a rest after overexertion. Good luck! Could be an active discussion.