Book Club to New Worlds - Annihilation by Jeff VanderMeer

Area X has been cut off from the rest of the continent for decades. Nature has reclaimed the last vestiges of human civilization. An expedition of four women is sent to collect data: a psychologist, a surveyor, an anthropologist, and our narrator, a biologist. Previous expeditions ended badly, with group members disappearing or returning as shells of their former selves, but little is known about what actually occurred on those trips.