Looking for an escape from her recurring nightmares, 18-year-old Sarah submits to a university sleep study, but soon realizes she's become the conduit to a frightening new discovery.

After hearing a child screaming for help from the green depths of a vast field of tall grass, Becky, a pregnant woman, and Cal, her brother, park their car near a mysterious abandoned church and enter the field, discovering that they are not alone and, for some reason, they are unable to escape a completely inextricable vegetable labyrinth.