This movie is about a mother (Alice Maguire) and her three daughters who are trying to get to the airport to pick up Mr Maguire, the daughter's father. But on the way there is a tornado warning and the trip starts to get too dangerous so they stop on the highway and run to a house to take shelter. Nobody answers the door so they all get in to the cellar to wait out the storm. But then they discover that there is somebody in the house above them, and then they become trapped in the cellar. But there's more to worry about than the impending storm, and their lives become endangered, by something that's not normal.