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. After hearing a young boy's cry for help, a sister and brother venture into a vast field of tall grass in Oklahoma but soon discover there may be no way out...and that something evil lurks within.