As the Conover family drives from L.A. to Chicago strange things begin to happen. Nine year old Michael sees a face form in the window of the family car. Two creepy children stare at fourteen year old Alison at a motel. A car follows the family for many miles, then hits their car and drives away.
Wherever the Conover family goes, wherever they look, they see a large woman and her children coming closer. The woman and her children are superhumanly strong. They can enter a locked room without opening the door.
Confused and scared, the Conovers can't comprehend what is happening to them. Everywhere they turn they see the woman and her children. The woman is Mama, and as she teaches her children, like a lioness teaching her cubs to hunt, the Conovers realize that they are the prey.