Three books, "Annihilation", "Authority" and "Acceptance"
Strange books about "Area X" where modern equipment doesn't work and the air is pristine. Different search parties are sent in, covered by Annihilation. Authority describes the Southern Reach, the research station and its political and power games, and finally Acceptance is an amalgamation of these, of past and current, of the Area growing. Never is everything completely explained, but enough so, but you'll have to read up to and including book 3 to figure things sorta out.
