A private detective searching for a killer comes across a satanic cult from another dimension, monsters called up from hell and murderous ninja assassins.

After a lengthy space mission, two astronauts (Steve Barkett and Larry Latham) return to an Earth transformed by nuclear war. As renegade gangs and mutants rule Los Angeles, the astronauts join two pretty women and a couple of kids in a growing resistance movement. This sci-fi adventure follows the men as they battle bell-bottomed biker leader Cutter and his brutal gang.