On a distant planet, a rural community of farmers fight for their livestock as well as their lives, against an alien monster threat, using homemade mechanical suits loaded with guns, missiles and lasers. When their numbers prove to be too great, the more vulnerable families retreat to an underground bunker while the mech drivers buy them time, sometimes with their lives. Finally, as a giant-sized alien monster threatens the bunker, the mech pilots and their families work together to defeat it and save everyone.