Pola X

In a picturesque Normandy chateau, Pierre (played by) lives a life of carefree indulgence alongside his widowed mother, basking in the rising fame of his pseudonymous literary endeavors. His visits to Lucie, his childhood friend and soon-to-be fiancée, at her parents' chateau only add to his sense of contentment. However, this idyllic existence is disrupted by a chance encounter with his cousin Thibault, a stockbroker, who invites Pierre to stay at his Parisian apartment but raises concerns about the mysterious young woman following him. As Pierre turns to gaze after her, she vanishes into thin air.

A later drive through the forest finds Pierre face-to-face with this enigmatic figure, whose haunting resemblance to a ghostly apparition from his dreams sends shivers down his spine. Introducing herself as Isabelle, Pierre's half-sister, she recounts her troubled past and that of her two companions - Razerka, a Romanian woman, and the small girl - refugees fleeing conflict in Eastern Europe.

Abandoning all sense of security and normalcy, Pierre takes Isabelle under his wing, and together they venture to Paris. A visit to Thibault's apartment ends in disappointment as the stockbroker brutally dismisses their presence, leaving them without a roof over their heads. Fearful of deportation, the trio finds solace in a seedy hotel on the city streets.

As Pierre becomes increasingly disillusioned with his own creative pursuits, he begins to reject his juvenile ideas for a second novel in favor of a gritty, mature work that reflects the hidden truths of life. However, his publisher is skeptical, warning that his pursuit of harsh realities will result in affected and inferior writing compared to the youthful innocence that comes naturally to him.

A chance encounter at the zoo between Pierre and the small girl takes an unsettling turn when she innocently shares her observation about humans stinking with random passersby. Her subsequent slapping by a stranger and fall resulting in a fatal head wound leaves Pierre feeling helpless and anxious. Fear of deportation drives them to seek refuge in a rundown warehouse commandeered by a terrorist cult, who promise safe passage for Razerka to meet a mysterious acquaintance.

In exchange for their protection, the group allows Pierre and Isabelle to join their ranks, immersing themselves in guerrilla warfare training and industrial music practices. As they succumb to the all-consuming passion that had been building between them, it becomes clear that nothing will ever be the same again.

As Pierre's mind wanders in a haze of grief, his scribbles on paper become an escape from the crushing news of his mother's passing (a sorrowful event that seems to have been shrouded by secrecy). Meanwhile, winter has taken hold of Lucie, her body wracked by recurring fevers, as she stumbles upon Pierre in a warehouse, her presence marked by a false identity born out of a misguided desire to shield Isabelle from the harsh reality of his abandonment. This act of devotion is rooted in her love for Pierre, which compels her to accept his disappearance and relationship with Isabelle without protest.

Isabelle, struggling to find her place within this fragile web of relationships, throws herself into an effort to ingratiate herself with both Lucie and Pierre, offering to care for Lucie during her periods of illness. As the winter days blend together, Pierre's creative endeavors continue uninterrupted; in his subconscious, he envisions a surreal scene where he and Isabelle are consumed by the red waters of a river, their bodies intertwined in a macabre dance.

The trio's walks along the Seine become a refuge from the turmoil brewing within them. During one such stroll, they stumble upon an autobiography penned by Pierre's father – a discovery that sends shockwaves through Isabelle's psyche as she fails to recognize the man on the cover, a revelation that had previously been withheld from her. This newfound uncertainty gnaws at her, and in a desperate attempt to assuage her doubts, she attempts to take her own life, only to be found by Thibault in a hospital bed.

Pierre's manuscript, submitted anonymously to his publisher, is met with brutal rejection, leaving him feeling defeated and disheartened. Isabelle confronts Pierre about his deception, her words laced with pain and betrayal. As Pierre's world begins to unravel, he becomes aware of the depths to which Lucie has sunk, her life reduced to a desperate struggle for survival in a squat. This realization sparks a sense of despair within him, and he accepts Thibault's invitation to engage in fisticuffs, stealing two handguns from the cult to confront his cousin in the heart of Paris.

The encounter ends with Pierre shooting Thibault in the head, only to be taken into custody soon after. As Isabelle watches Pierre being led away in handcuffs, her heart shattered by the loss of their relationship, she throws herself in front of a vehicle, her body broken and battered on the pavement.