Four people traveling in a van run over a lone woman while she is walking in the dark down a country road. After loading her into the vehicle to take her to the nearest hospital, they notice that she is behaving rather strangely. The occupants of the van soon realise that the time has come to fight for their lives, and together they agree on one very simple rule: "do not sit next to her."
On a secluded farm in a nondescript rural town, a man is slowly dying. His family gathers to mourn, and soon a darkness grows, marked by waking nightmares and a growing sense that something evil is taking over the family.