In 1866, against the turbulent backdrop of the Austrian occupation of Italy during the Third Italian War of Independence, Countess Livia Serpieri attends a patriotic opera with her cousin, Marchese Roberto Ussoni. During a passionate and politically charged altercation, Ussoni confronts Austrian officials, but the Countess's attentions are drawn toward a dashing Austrian officer, Lieutenant Franz Mahler. A forbidden and tumultuous love affair ensues between Livia and Franz. Consumed by her passion, Livia jeopardizes her social standing and her marriage, and her previously staunch nationalist sentiments begin to fade.

Livia's obsessive love for Franz grows as he begins to exploit her for his gain, leading to a chain of deceptions and moral compromises. Her once stable and secure life is rapidly unraveled by the intensifying conflict and her all-consuming desire. At a crucial juncture in the war and their relationship, Livia faces a harrowing decision that will decide her fate and possibly alter the course of her nation's struggle for freedom. The consequences of her actions unfold amidst the grand historical context, revealing the profound personal costs of love and betrayal during times of political upheaval.