 Vorelli is a ventriloquist & hypnotist, with an amazing dummy, Hugo. Vorelli meets and pursues a beautiful heiress (Marianne); he mesmerizes her, and induces a baffling coma. His buxom mistress (Magda) fears he ll dump her for the younger woman, and threatens to expose him. Vorelli tricks Hugo into killing Magda while he s safely elsewhere. Marianne s boyfriend Mark investigates. He discovers another killing in Vorelli s past, of a man called Hugo. The girl wakes from her coma, and announces she will marry the hypnotist. When the triumphant Vorelli tells Hugo his plans for Marianne and a new, female dummy, a final confrontation yields surprising results.