Five friends are traveling through rural Nebraska on a weekend getaway when their SUV is suddenly attacked and forced off the road by a flock of wild crows. Upon waking up, they discover that one of their party, Johnny, is missing. Seeking help, Brian and Scott head through a cornfield to a nearby house, hoping to find Johnny there while leaving Brian's girlfriend Natalie with Chris at the car. As they near the house, they encounter a clearing with a scarecrow hanging on a scaffold in the center before finally leaving the field.
On entering the house, they find it seemingly abandoned and in a state of decay. Back at the road Nicole sees a young boy who disappears into the cornfield and immediately afterwards encounters another scarecrow lying beside the road. On further inspection she discovers to her horror that the scarecrow has teeth and when Chris doesn't believe her she runs into the field to find Brian. As Scott and Brian explore the house further, they find a horribly multilated Johnny on the second floor working at a sewing machine and he ignores their terrified attempts to gain his attention. He suddenly stops working just as Natalie is attacked and killed by an extremely fast assailant and her body dragged away in front of a frightened Chris. Hearing her screams, Brian runs into the field only for him and Chris to find her now lifeless body strung up in the clearing. In anger, Brian chases after her killer, leaving behind Chris, who flees in terror on seeing a strange force entering Natalie's eyes. Brian tackles the murderer only for it to be revealed as a scarecrow as a second one attacks and forces him to run towards the house.
After regrouping, they discover that Johnny has disappeared and the shaken trio are forced to come to terms with their friends deaths. They then begin looking around for a means of escape through use of one of the abandoned cars littering the yard. In their search, Brian and Scott enter a barn where Scott hallucinates seeing a farmer and his two sons named Corey and Alex, the former of whom is physically abused by his father as his brother looks sheepishly on. After regaining his senses, the baffled Scott attempts to convince Brian of what he had seen. At the house, Chris sees the young boy as well and follows him towards the room that Johnny was found in and is thrown into a state of panic when the clearly dead Natalie walks into the room and sits down at the sewing machine. As she begins to make a scarecrow mask, the door slams shut, trapping the frantic Chris inside. Hearing his cries for help, Scott and Brian attempt to open the door to no avail and Chris finally manages to escape through the window but not before the panel slams shut on his hand, causing him to fall. Brian tries to stop Natalie before she disappears but is too late as she is already gone.
Later Scott suffers yet another vision and this time witnesses Corey kill his older brother with a pitchfork out of jealousy and anger of Alex's better treatment. He then dresses him as a scarecrow and leaves him in the cornfield, thus revealing that it is Alex's vengeful spirit inhabiting the scarecrows. On returning to the present, Scott realizes he has wandered into the clearing and is attacked by a scarecrow before being saved by Brian. The scarecrow chases them until they reach the edge of the cornfield and discover that it cannot leave the field and merely stares at them before leaving. Afterwards Chris attempts to convince Scott that Brian has become unstable in his attempts to find Natalie and to leave with him in the truck discovered in the barn. Scott refuses and leaves to find Brian in the house.
In the cellar, Scott witnesses Corey's spirit and he and Brian find his body, revealing he had died from a self-inflicted gunshot wound. Outside, Chris hot-wires the truck and tries to escape through the cornfield only to be assaulted by Alex switching between numerous scarecrows at will. Chris rips the mask off of one and breaks the ghost's hold on the body, discovering that it is Johnny's corpse. Brian then saves him only to be killed by the scarecrow form of Natalie when he can't bring himself to shoot her. Chris and Scott then return to the house despondently and ponder their fate. Scott eventually figures out that the only time they are safe to enter the field is when Alex is busy possessing the body of a victim and sewing together a new mask as he can only occupy one body at a time. As he is busy possessing the newly deceased Brian, Chris and Scott put together a plan to burn down the corn field with gasoline. However Alex realizes that they are about to escape and finishes before they are ready. Immediately they are attacked by numerous scarecrows but they are all killed by Chris and they agree to split up to have better chances of survival. As Chris makes his way to the road, he is jumped by the undead Brian and is impaled on a fence. He then desperately tears off Brian's mask as he gets back up only to hear yet another scarecrow closing in on him. Hearing Chris's screams, Scott tries to set fire to the field only for Alex's original scarecrow body to suddenly appear and knock him unconscious.
On waking up, Scott finds himself in the clearing with Alex who has strung up Chris on the scaffold. Remembering his vision, Scott finds the pitchfork dropped nearby and stabs Alex repeatedly with it only for him to get back up and attempt to kill him. Chris grabs Alex and holds him in place to give Scott enough time to escape. Alex then kills Chris and gives chase after Scott, who frantically runs towards the road. Scott finally manages to make it out of the field and collapses in exhaustion as he sees a couple drive up and begin searching for the occupants. Due to his injuries, he is unable to speak and looks on in horror as he sees the scarecrow, who gives him a sinister glance before lying back down on the side of the road. The couple then see Scott as he looks at them in shock and the film cuts to black.