Ailing 83-year-old Sigmund Freud, his wife Martha, and daughter Anna settle into a new home in London after being forced to flee Austria. Flashbacks recall Freud's early professional life, ambitions to do important work, and engagement to Martha, whose sister Minna is also engaged. Freud experiments with cocaine as a cure for morphine addiction and other uses, prompted especially by his relationship with Ernst von Fleischl-Marxow.

Paris, 1885: Freud goes to Paris to study under Jean-Marin Charcot, who has been experimenting with hypnosis to treat patients with 'hysterical' neuroses. Returning to Vienna, his advocacy of Charcot's techniques is largely rejected, especially by his superior, Theodor Meynert. With the aid of Josef Breuer, Freud begins to use hypnosis to treat patients, particularly the Baroness von Lieben. His work leads him to begin investigating the role of dreams and repression of memories.

Vienna 1891: through his practice, self-examination, and friendships with Breuer and Wilhelm Fliess, Freud develops his concepts of the unconscious and the role of desire, beginning to posit sexuality as a source of psychic conflict and to develop his 'seduction theory'.

An intriguing new relationship develops when Minna Bernays, Freud's attractive sister-in-law, joins the family. Freud's recent theory has outraged Vienna, leaving him, professionally, more isolated than ever. With Martha consigned to maternal duties and the Fliess friendship deteriorating, increasingly, Minna alone shares Sigmund's private frustrations until the celebrated 'Oedipus' theory ensures his future.

Vienna 1907: The movement of psychoanalysis is born. Freud's revolutionary theories appeal to a growing band of supporters—Adler, Stekel, Federn, Rank, Ferenczi—who passionately participate in the 'Wednesday Society'. Of the newfound disciples, Carl Jung is the master's favourite. In this distinguished Swiss gentile, Freud sees the key to promoting the group's image beyond that of a Jewish cabal and, more importantly, the personal relationship he constantly craves.

London, 1939: Psychoanalysis flourishes in America and Freud's works are sought worldwide: his international standing has far surpassed his father's simple plea that he make professor. But in the prophet's own land, it is a different matter. More cautious friends have persuaded the elderly Sigmund to take refuge in England and it is there that he completes the final, revealing session of self-analysis.