A Man of Genius portrays a psychological journey from safety into obsession and secrecy. It mirrors a physical journey from flamboyant Regency England through a defeated Europe struggling to create a new order after the upheavals of the Napoleonic conquests.

Ann, an author of cheap Gothic novels, becomes obsessed with Robert James, regarded by many, including himself, as a genius; she is captivated by his Romantic ideas, his talk, and his band of male followers. The pair leaves London for occupied Venice, where Ann tries to cope with the monstrous ego of her lover. The relationship grows tortuous as Robert descends into violence and near madness. Forced to flee with a stranger, she delves into her past, to be jolted by a series of revelations— about her lover, her parentage, the stranger and herself.