When a bunch of hippies, a couple of lesbians, and a stripper are kidnapped along with others, they wind up at the estate of eccentric old Dr. Humpp, who seeks to turn them into nonstop sex machines, with the aid of a few aphrodisiacs and properly prepared brainwashing (thanks to the requisite sentient brain-in-a-jar). Soon these unfortunates are unable to control their baser urges and find themselves in a state of sex-o-mania! While the poor couples copulate, the savage Dr. Humpp drains away their vital energy, which he uses to refresh his unending youth.