A present day rancher's home is invaded. His wife and son are killed, leaving him with only an elderly aunt who has Alzheimer's. They escape into the desert to a cliff dwelling hideout where a neighbor has also taken refuge.
The intruders come after them, intent on erasing any witnesses to what they are really doing. The rancher discovers the real reason they want to take and hold 20 square miles for two days.
The rancher has to fight off the assault teams, using long dormant skills learned in his old profession, and then he and his neighbor discover the secret with which they must cope, all the while protecting themselves and the old woman.