Victoria stumbles upon her husband Calvin’s crimes, only to be framed as a murderer by him — a powerful elite lawyer with ties to the governor. She is sent to the high-security Salvador Women’s Prison to await execution. With her sister’s days numbered, Emma, who helped design the prison, decides to take desperate action. She tattoos the entire prison layout and escape routes onto her body, then commits a robbery on purpose to get incarcerated as a felon, bent on rescuing her sister.
Yet this death trap, ringed by sharks, infrared alarms and heavy surveillance, proves far deadlier than expected. Emma searches for drainage systems, the infirmary and blind spots in the camera network. Meanwhile, she goes from clashing to forging an alliance with Tara, the prison’s self-proclaimed queen, and navigates the wary, ambivalent help from prison doctor Allen.
Outside the walls, Calvin wields his influence to hunt the sisters down. A mysterious assassin codenamed Black Mamba also infiltrates the prison to sabotage their escape. As the execution date draws near, Emma, Victoria, and Tara — also a victim of betrayal — lean on one another through riots, traps and life-or-death perils. Together they challenge the supposedly inescapable fortress. What they seek to break free from is not merely a prison, but a cage woven from lies, betrayal and power.
