"Hellclerk" is a great idea. Of course legalistic officious evil would have clerks and bureaucrats.
I really like the clean layout. I think this would be enhanced with a touch of spot art, if you wanted to drop a well chosen piece or two in.
I like the central mystery and that it's not strictly necessary to visit every location to figure out what happened with the contract. (I'm not sure parties will necessarily be exploring the tavern basement, for instance.)
Nicely creepy while still likely not being too much for more sensitive players.
Well done!