In Lang's last German film before emigrating to the U.S., terror reaches beyond the domain of the eye. Mabuse's demonic power returns through the testament he writes while in total confinement, under the scrutiny of prominent psychiatrist Dr. Baum, and comes to life through the orders that a mysterious criminal, "the man behind the curtain," imparts to his henchmen. Who is this invisible evildoer, if Mabuse is a prisoner in the asylum? Who executes Mabuse's will with uncanny precision? Perhaps, no one in particular, because evil in this film, which masterfully uses sound and the technologies of recording, is dispersed through the ether, and can no longer be tracked back to any single character. For Inspector Lohmann (Otto Wernicke), set on the trail by a dramatic phone call, what is left is only the patient deciphering of effaced traces-a name written in reverse on a window pane, the muttering of a witness who has gone mad before speaking the truth.