After a young, middle-class couple moves into what seems like a typical suburban house, they become increasingly disturbed by a presence that may or may not be demonic but is certainly the most active in the middle of the night.
An unprecedented series of violent tornadoes is sweeping across Oklahoma. Tornado chasers, headed by Dr. Jo Harding, attempt to release a groundbreaking device that will allow them to track them and create a more advanced warning system. They are joined by Jo's soon to be ex-husband Bill, a former tornado chaser himself, and his girlfriend Melissa.
On the day of his scheduled execution, a convicted serial killer gets a psychiatric evaluation during which he claims he is a demon, and further claims that before their time is over, the psychiatrist will commit three murders of his own.
