John "Control" Rodriguez takes over as the new director of the Southern Reach, a government agency formed to manage a coastal region named Area X.

Control methodically sifts through the accumulated data (interviews, photos, videos) and discovers that there have been many more expeditions into Area X than have been disclosed to the public.

The biologist mysteriously reappears in a vacant lot and is detained by the Southern Reach for debriefing; Control begins interrogating her.

However, she is uncooperative, insisting that she is not the biologist and requesting that Control refers to her as Ghost Bird; after initially failing to gain any information about Area X or what happened there, his tactics become increasingly more unconventional.

As he runs upstairs in terror, he sees that the border of Area X is moving, encroaching on the facility and leading with it a replica of the director.

Based on his intuition and knowledge of the biologist's background, Control travels to the site of an old field study she had conducted before she came to the Southern Reach, with Central close behind despite his efforts to dodge their agents.

Control finally meets Ghost Bird at a remote location where she has unexpectedly created another portal to Area X at the bottom of a pool of water, a gateway that she believes has formed from a "brightness" she carried that has run its course through her.

"[4] The New York Times also gave Authority favorable review: As in the first book, VanderMeer also performs a careful character study of one of the few people strange enough to contend (debatably) with Area X.