It is the late eighteenth century in Mozart's Vienna. On a cold January day, flamboyant practitioner Mesmer is summoned to the house of the Court Secretary and entreated to restore the eyesight of his daughter, a piano genius. In his colourful, chaotic private hospital, amongst other patients with varying hysterical disorders, he gradually wins her trust and submits her to a series of controversial treatments based on animal magnetism, the "laying on of hands". Soon he is able to restore her sense of darkness and light, and his methods appear to be successful.
Besieged by new patients, he is certain that fame and imperial recognition lie ahead, but as Maria's eyesight returns, her musical talent appears to diminish and Mesmer is branded a charlatan. Worse still, rumours begin to circulate that he has been taking advantage of this young patient; their closeness has been noted, and his methods have been salaciously interpreted.
Mesmer sets out for Paris, keen to try his luck elsewhere, and there years later he is reunited with Maria, a blind musical prodigy once more. Mesmerized is a lyrical novel full of atmosphere and sensuality in which Walser has brought Mesmer, a controversial figure who trod the narrow path between science and magic, vividly to life.