In 18th century Vienna, middle-aged Dr. Mesmer believes that he can cure physical and mental diseases by manipulating a force within the body that he calls "animal magnetism." The only patients who seem to respond to his treatments, however, are troubled young women who react ecstatically to his caressing therapeutic touch. He makes particularly good progress with a blind teenager whose sessions with Mesmer provide her with a means of escape from her father, who's been raping her. At one point the girl hits her head, and regains her sight; Mesmer takes the credit, and they seem about to embark on an affair. However, Mesmer's jealous wife and the medical authorities conspire to have him exiled from Vienna. He relocates to Paris and becomes a deliberate quack, exploiting his magnetic therapy methods to provide bizarre entertainment for fashionable court ladies. His French medical colleagues hold a hearing against him, calling in his former patient, who is now blind again, to testify against him. At the last moment, an approaching mob of revolutionaries forces the doctors to scatter in panic, leaving Mesmer alone with the girl. She accuses him of abandoning her. Sadly, he tries to explain himself.