Act I - Venice
A mass in honour of the new French Ambassador Cardinal de Bernis. Among the church clerics is aspiring priest Giacomo Casanova who has arrived late with his pupils the Savorgnan sisters. In the congregation is Father Balbi who has with him a book forbidden by the church. Balbi gives the book to a curious Casanova. After the mass the Three Inquisitors accost Balbi believing him to be still in possession of the forbidden book.
Later, Casanova is seduced by the Savorgnan sisters. They are discovered, and Casanova is forced to forgo his church career. He is left with only his violin and book.
Casanova joins a group of musicians auditioning to form an orchestra for Senator Bragadin’s masquerade ball. Casanova earns a place as does Manon Balletti, a cellist. Despite the arrival of his guests, Bragadin is more interested in his attractive new violinist, Casanova. Casanova becomes increasingly intrigued by the cellist Balletti, and at the end of the evening, after the orchestra is paid, they leave together.
On their way to find a gondola, Casanova and Balletti are set upon by thieves. She escapes but Casanova is robbed of his wages - though not his book - and left for dead. Bragadin appears. He takes Casanova back to his palazzo, tends to his wounds and shows him his library of philosophical and forbidden works. Bragadin attempts to seduce Casanova but his efforts are curtailed when the senator suffers a stroke. Casanova administers basic medical aid, guided by his book. Bragadin credits Casanova with his recovery and declares him his heir. Casanova’s elevated status does not go unnoticed by the Three Inquisitors.
A mass is said in celebration of Bragadin’s recovery, presided over by Cardinal de Bernis. As Casanova leaves, a note from a nun ‘M.M’ is passed to him. Meanwhile at the prison of the Inquisition, under torture to confess who has the forbidden book, Father Balbi gives up Casanova’s name.
Cardinal de Bernis’ apartment
Following the instructions on the note, Casanova arrives at Cardinal de Bernis’ luxurious private apartments. M.M. arrives and sets about a staged seduction of Casanova for the benefit of her hidden lover, the voyeur de Bernis. Suddenly they are interrupted by Bragadin who warns Casanova that the Inquisition is coming for him. Casanova tries to flee Venice but he is caught and imprisoned.
Act II - Paris
Bellino and Henriette
Two women, Bellino and Henriette are leading almost parallel lives. Bellino’s brother persuades her to dress like him so she can masquerade as a male castrato singer. Elsewhere Henriette is subjected to violent abuse by her husband. She dresses as a soldier and flees, leaving her baby.
At the gaming table
At a Paris gaming salon a poorly dressed hustler, Casanova, attracts attention as he tells the story of his escape from prison, moving from table to table advising the players on tactics. Madame de Pompadour arrives and in the corner a group of soldiers sit, including the disguised Henriette who intrigues Casanova but flees when her husband enters. Observing everything, Madame de Pompadour asks Casanova to be brought over where he tells her the story of his escape. Feeling they are kindred spirits she takes him to Versailles and becomes his benefactor.
Casanova, now rich, carefree and reckless, sets about the social and sexual conquest of Paris.
Dancing on the Precipice
Casanova throws a party. He auditions musicians and amongst them is his old acquaintance Balletti. Bellino too earns a place and Casanova, uncertain of her true gender, is perturbed and intrigued by her. A great party ensues but as it comes to a close, Casanova is left on his own. He picks up a book and begins to write.
Casanova poses at his desk while an artist paints his portrait. He is determined to be depicted as an intellectual.
Bellino arrives, admires Casanova's intents as a writer and in turn, shares her secret - that she is a woman. Liberated, leaves. Casanova returns to his writings and works feverishly before gathering his papers to take to the printers.
Casanova stumbles into Henriette. She reveals her tragic story and moved, Casanova offers her shelter...and more. Madame de Pompadour arrives; she has arranged a meeting between Casanova and Voltaire. Suspecting Casanova is hiding someone, she and Voltaire leave. Casanova begs Henriette to wait for him and rushes off after Voltaire to whom he confidently explains his theory of cubic geometry, only to be mocked.
In Casanova’s absence Henriette’s husband arrives and convinces her to leave with him. Casanova returns to his apartment and finds Henriette has gone with only a letter left behind. Despondent, he attempts to escape into the world of sensuality.
Henriette unexpectedly returns and finding her worst fears about Casanova confirmed, rejects him forever.
Increasingly haunted by visions of his past, Casanova goes to throw himself into the abyss
A single page flutters down and Casanova is brought back from the brink by the simple thought of writing. Former lovers and figures from his past dance in his mind’s eye, the human touch of history to be memorialised in his History of My Life.