Cincinnatus is a former kindergarten teacher arrested and convicted of "gnostical turpitude," a vague charge related to his inability to hide his true self in an oppressive, conformist society. He is deeply alienated, having grown up in a state orphanage and spending his life trying to feign normalcy. In prison, he struggles to record his thoughts while desperately seeking the date of his scheduled execution.

M'sieur Pierre is a compliant, cheerful man who arrives at the prison fortress as a fellow inmate. He seemingly embraces his confinement with enthusiasm, viewing the rules and traditions with an easygoing attitude. He is highly favored by the prison staff, who hold him up as a model prisoner in sharp contrast to Cincinnatus's sullen demeanor.

Marthe is Cincinnatus's wife, a woman defined by her frequent and unhidden infidelities. She commands Cincinnatus's unwavering devotion despite her constant betrayals and unapologetic affairs with multiple lovers. She is deeply embedded in the conformist society that condemned her husband, prioritizing her own comfort over his plight.

Rodrig is the extravagant and personable director of the prison fortress. He takes immense pride in overseeing the confinement of his inmates, but his management style relies more on theatricality and a desire for social pleasantry than logical protocol. He expects his prisoners to be cheerful and is personally offended when they do not play along.

Rodion is the primary turnkey and jailer at the prison fortress. He performs his duties with a bizarre mix of rough authority and strange intimacy, occasionally offering to waltz with his prisoner or singing songs loudly. He maintains a pet spider in the cell, showing the arachnid more care than he shows the human inmate.

Roman is Cincinnatus's defense lawyer, an ineffectual man prone to confusing matters with legal jargon. Rather than defending his client's life or rights, Roman focuses entirely on bureaucratic formalities and becomes deeply distressed when paperwork is damaged or procedures are questioned.

Emmie is the young daughter of the prison director. She roams freely throughout the imposing fortress, undermining its oppressive atmosphere with her childish games and unpredictable behavior. Her presence introduces a strange element of mobility within the strict environment.

Cecilia is Cincinnatus's mother, a woman he hardly knows since he was raised in a state orphanage. She arrives at the fortress for a strained visit, sharing superficial observations and stories about strange objects from her childhood. Despite their estrangement, she shares a strong physical resemblance with her son.

The librarian is a silent, aloof prison staff member responsible for distributing reading material to the inmates. He refuses to engage in conversation or participate in the bizarre social games encouraged by the prison director, strictly focusing on his arbitrary cataloging system.

Diomedon is Marthe's son, conceived during one of her many affairs. Born with disabilities, he was initially placed in the kindergarten class where Cincinnatus once taught before being raised in their household. He is a disruptive presence during family visits.

Pauline is Marthe's daughter, also fathered by one of Marthe's lovers rather than Cincinnatus. She arrives at the fortress during a chaotic, crowded family visit, adding to the overwhelming noise in the small cell.

The patriarch of Marthe's family uses the rare opportunity of a prison visit to relentlessly criticize Cincinnatus. He openly demands explanations for Cincinnatus's criminal behavior rather than offering any comfort to the condemned man.