Evil Zinger 16: Process of Illumination (cipher)

In this Process of Illumination puzzle, the given numbers have been replaced by letters; all instances of a particular letter represent the same number, but two different letters must represent different numbers. The rules are otherwise unchanged.

(click to enlarge)

And that wraps up another batch of Evil Zingers (EZ's)! I decided to save the biggest and evilest one for last. I'd like to thank my readers for the astounding feedback they've given me, particularly on my Monday Mutant series; without you, these EZ's wouldn't exist. :)