A tough sergeant helps a raw recruit find courage under fire during the Korean War.

Professional killer Bus Crow is hired by cattlemen to eliminate squatters. When Marshal Sam Rochelle is sent to investigate, saloon owner Hallie has to be a reluctant witness.

The residents of a small town are excited when a flaming meteor lands in the hills, until they discover it is the first of many transport devices from Mars bringing an army of invaders invincible to any man-made weapon, even the atomic bomb.