The plot begins on August 10th in a California drive-in theatre, and concerns a killer on the loose, with the victims beheaded with a large sword.

Manos was written, directed and produced by Harold P. Warren, a fertilizer salesman from El Paso, Texas. Warren also starred in the film. A vacationing family is trapped at a lodge maintained by a polygamous pagan cult. It ranks among the best movies ever made by a fertilizer salesman.