: The ruthless, calm, and manipulative "King" of the prison who controls everyone within the walls.

: The syndicate is led by Ik-ho (Han Suk-kyu), an inmate who has the warden and guards in his pocket.

: Under Ik-ho’s leadership, prisoners are allowed to leave the facility at night to commit high-profile crimes—including murders, heists, and blackmail—before returning to their cells, providing them with a perfect alibi.

: A prominent inmate and part of Ik-ho’s inner circle.

: An intelligent and reckless ex-cop on a dangerous undercover mission.

: Yoo-gon’s true goal is to gain Ik-ho’s trust to expose the syndicate and uncover the truth behind his journalist brother's death. Key Characters & Cast

is a South Korean action-crime thriller that follows an undercover detective who enters a high-security penitentiary to dismantle a crime syndicate operating from within. Directed by Na Hyun , the film is known for its gritty atmosphere and high-stakes power dynamics. Core Premise & Plot