A spaceship returns to Earth after several years of space exploration and finds it desolate. Landing in what they believe is Mexico, the crew decides to travel north, and try to find out what happened to Earth during the years they were gone.

A spaceship returns to Earth after several years of space exploration and finds it desolate. Landing in what they believe is Mexico, the crew decides to travel north, and try to find out what happened to Earth during the years they were gone.