Chronicles the last great American showman, filmmaker William Castle, a master of ballyhoo who became a brand name in movie horror with his outrageous audience participation gimmicks.Chronicles the last great American showman, filmmaker William Castle, a master of ballyhoo who became a brand name in movie horror with his outrageous audience participation gimmicks.Chronicles the last great American showman, filmmaker William Castle, a master of ballyhoo who became a brand name in movie horror with his outrageous audience participation gimmicks.