In 1924 Paris, a 14-year-old Gilda Besse (Charlize Theron), the daughter of a French aristocrat named Charles, finds her life altered when a fortune teller forewarns her, revealing that her life line suggests she won't make it past 34.
Flash forward to a stormy 1933 night, Gilda crosses paths with Guy Malyon (Stuart Townsend), an Irish scholarship student at Cambridge University. After a conflict with Julian Elsworth (Gabriel Hogan), one of the university dons, Gilda unexpectedly seeks refuge in Guy’s room. They spend the night on opposing sides of the bed, and the tension makes it evident that their connection is neither simple nor platonic. Guy’s backstory reveals his father as a policeman in Dublin who was tragically killed amidst politically charged upheaval, while Gilda's glamorous background is intertwined with the world of champagne and American aspirations.
As their complex relationship unfolds, Julian learns of Guy's kindness towards Gilda and invites him to a lavish party, where their differing worlds collide. Gilda is soon caught in the extravagant lifestyle surrounding Julian, ultimately leading her to engage deeply with Guy, provoking jealousy and unexpected emotions. After a whirlwind romance, Gilda is compelled to return to America following her mother's death, leaving Guy behind.
Years pass, and Guy emerges as a teacher amid the turmoil of the Spanish Civil War, passionately supporting the fight against Fascism. His life takes an unexpected turn when he sees Gilda as an extra in a Hollywood film and receives an invitation to Paris, where she is now a photographer. Upon arrival, he learns she shares a life with Mia (Penélope Cruz), a nursing student and model, complicating their reunion. Gilda and Guy rekindle their passionate relationship, much to the dynamic of their unconventional trio.
Yet, the warmth of their bond begins to falter as the realities of political strife encroach on their lives. Gilda introduces Guy to her father, who had remarried, while personal tumult escalates when Mia faces violence from her partner, Lucien. In an act of vengeance for Mia, Gilda takes matters into her hands, revealing her fierce nature while struggling to balance her affluent lifestyle with her evolved convictions.
As the shadows of war grow darker, both Guy and Mia choose to act against the currents of the ongoing conflict, emphasizing their dedication to the Republican cause. By 1938, Guy dons the uniform, while Mia tends to the wounded – both are fervently engaged in a war that both claims and hardens their hearts.
Mia's fate tragically intertwines with this chaotic backdrop, leading to further unraveling of their intertwined lives. Guy, now engulfed in a world of espionage, learns of Gilda's involvement with a Nazi officer, which ultimately shatters his world when she dismisses him upon their reunion.
As the story crescendos, Gilda's journey culminates in occupied Paris, where her legacy rests precariously. After she aids in Guy's escape, her fate becomes entwined with tragic inevitability, culminating in her untimely demise at the hands of those seeking justice for loss. The film concludes with Guy reflecting upon Gilda's last letter, enveloped in grief and tumultuous memories of a love torn asunder by war and betrayal.
