As far as romance goes, Jakob Sammelsohn is fairly incurable. A young Jewish occulist, he is twice married - once divorced and once widowed - all by the age of twelve. He finally flees his small village and his pious, vengeful father, and makes his way to dazzling Vienna. Surrounded by intellectuals on the forefront of knowledge and living in a place bustling with innovation, Jakob begins to think he is being followed; a plaguing spirit trails Jakob throughout the novel and challenges his beliefs in a world of science. Travelling from Vienna to Warsaw, Jakob finds three mentors, all real-life luminaries: Sigmund Freud, who is just beginning to raise eyebrows with his early work in psychoanalysis; L. L. Zamenhof, the founder of Esperanto, the utopian international-language, and Rav Kalonymos Kalmish Szapira, a rabbi who refuses to abandon his faith in the darkest moments of the Nazi genocide.