Malik El Djebena, a 19-year-old of Maghrebi descent, finds himself sentenced to six years in prison after a violent incident involving police officers. Arriving alone and illiterate, he soon becomes entangled with the ruthless Corsican mobsters led by César Luciani, who enforce an oppressive regime within the prison walls.
The prison itself is sharply divided into two factions: the Corsicans and the Maghrebis. Initially keeping to himself, Malik's life takes a turn when Luciani coerces him into becoming an assassin for Reyeb, a Maghrebi witness in a high-stakes trial. This dark deed unexpectedly earns him underground protection from the Corsicans, despite his North African background.
In this grim environment, Malik is relegated to a lowly servant role among the Corsicans, who treat him with contempt, yet he is tormented by the ghostly memory of Reyeb. As fate would have it, with many Corsican leaders either transferred or released, Luciani must give Malik greater authority. Seizing the opportunity, Malik learns Corsican in secret, positioning himself as Luciani’s informant inside the prison.
As he begins to gain privileges—including day-long furloughs—Malik is thrust into the underworld of crime, managing Luciani's illicit operations outside. During this time, he forges a deep friendship with Ryad, another Maghrebi inmate who teaches him to read and write. This newfound knowledge becomes a pivotal tool that increases Malik’s influence, as he connects with other Maghrebi inmates: Tarik and Hassan.
Malik’s journey takes a darker turn as he becomes involved with Jordi, a drug dealer in prison. When Ryad faces an early release due to testicular cancer, Malik and his friends devise a plan to establish a drug trade selling hashish. However, their operation faces a serious threat when Ryad is kidnapped by the ruthless drug dealer Latif. Malik, determined to rescue his friend, devises a daring plan: he kidnaps Latif’s family member and applies pressure on Latif's gang to secure Ryad's freedom.
As tensions rise, Luciani discovers Malik's clandestine activities during his day releases—leading to severe punishment. He sends Malik to connect with Brahim Lattrache in Marseille, another Maghrebi player who bears a deep grudge against the Corsicans for Reyeb's murder. When Malik faces threats from Lattrache but cleverly manages to avert danger by alerting him about deer on the road, Lattrache is impressed and agrees to align with Malik for criminal dealings, disregarding Luciani, even after Malik confesses to Reyeb’s assassination.
Luciani, suspecting a traitor among his ranks, plots to have Malik eliminate Jacky Marcaggi, the Corsican mafia's don for secretly negotiating with the Italian Lingherris mafia. Yet, Malik and Ryad, having grown more cunning and ambitious, hatch their own scheme: they kill Marcaggi's guards, kidnap him, and reveal that Luciani orchestrated the hit before leaving him behind.
Seeking refuge at Ryad's home with his friend’s family, Malik navigates the emotional turbulence as Ryad’s cancer recurs and he decides against further treatment, leaving Malik with a promise to look after his family. Upon returning to prison after his extended absence, Malik finds himself in solitary confinement, effectively shielding him from Luciani’s revenge. When he returns to the general population, he witnesses the downfall of Luciani's power as Marcaggi uses his influence to dismantle Luciani's faction.
At long last, on the day of his release, Malik is greeted by Ryad's wife and young son, and as they step into a new life, they are escorted by a convoy carrying Malik's new allies. Malik’s tale is one of survival and transformation in a world marked by crime and loyalty, forever haunted by the shadows of his past.
