US National Guard soldiers conduct exercises in the desert region of New Mexico. When they make another halt at the frontier outpost of the state, they are surprised to find that there are no people at the outpost. Soon, the military receives a strange distress signal coming from a remote mountain elevation, so they are sent to the area to help those in distress. Several soldiers remain at the outpost, in case someone appears, and all the rest go in search of the source of the distress signal. Soldiers do not even realize that the Carter family has been in this area not so long ago, but they themselves are lured into a trap and now bloodthirsty mutant cannibals are waiting for them.