Boris Karloff is at his mesmerizing best in this hypnotic chiller costarring Catherine Lacey (The Lady Vanishes) and directed by Michael Reeves (Witchfinder General). A disgraced hypnotist, Professor Marcus Monserret (Karloff) is about to have the last laugh. Inventing a machine that can control the minds of others, he lures Mike Roscoe (Ian Ogilvy) to his dingy flat to take part in a grand experiment. Discovering he can experience Mike's sensations as well as his actions, Monserret envisions his device as a boon to science. His maniacal wife (Lacey), however, embittered by years of poverty, soon overpowers her husband and proceeds to use Mike for her own selfish gain. The rarest of the three films directed by the gifted Reeves before his untimely passing.