A curious "gimmick" movie in the William Castle tradition (though not itself a Castle project), screenings of this film featured a hokey but creative "Hypno-Magic" process allegedly designed to hypnotize the theater audience. The otherwise mundane psycho-thriller plot features Jacques Bergerac as stage mesmerist "The Great Desmond," whose act includes hypnotizing entire audiences into performing rather dull Simon-says maneuvers and such. The real trick, it turns out, involves Desmond's Svengali-like seduction of his more comely female patrons -- most of which end up horribly disfigured the next morning, the victims of apparent self-mutilation. Thanks to several scenes hinting at the obvious hatred Desmond's wife and assistant, Justine (Allison Hayes), harbors toward her husband's pretty subjects, there's not much of a mystery here. Nevertheless, the police are baffled, leading one victim's best friend to set herself up as bait and trap the guilty party -- whose secret is revealed in the "shocking" climax. The Hypno-Magic gimmick, though certainly ineffective, provides some of the film's more hilarious diversions, and thoroughly disarms any potential for suspense.
by Cavett Binion synopsis