I really liked this one.
Nice to have a single-session Listener for once; enough thematic material that the derived quotation helped with the clueing, the author helped with the theme, and that the device - once identified - helped disambiguate the answers to certain clues.
Fermat did have *other* theorems than his last; not all Listeners have to be an easy gridfill: incredibly frustrating endgame - and the title was a nice touch.
Many thanks Dysart!
hw7