I'm a librarian who loves anime, manga, and reading a wide variety of genres.
This is probably not a good idea on my part, but some comments I got after I reviewed Annihilation made me decide to read the next book. It just came in via ILL. Whereas Annihilation was weirdness and exploration, the reviews make it sound like Authority is office politics and weirdness. It stars a completely different main character and takes place outside Area X.
Things I've learned so far (assuming they're not lies) that answer or add to questions leftover from Annihilation:
(show spoiler)