When Lena Owens accidentally killed the warden's son while resisting his assault, she was wrongly sentenced to death, with her execution set for seven days later. Her mother, Daisy, appeared to be nothing more than a frail housewife, but she was anything but. Twenty-five years ago, she herself had designed this very prison, and the complete escape route was tattooed on her back. To get close to her daughter, she robbed a bank with a sawed-off shotgun, deliberately allowing the police to incarcerate her. Inside, three women forged an unlikely alliance: to bore through concrete with a dental drill hidden in a prosthetic tooth, steal keys right under the warden's nose, pick every lock, and trigger a prison-wide blackout. Meanwhile, a distraught and ruthless warden pursued them relentlessly at every turn. The countdown to execution ticked down with every passing second. Can a mother rescue her daughter from the impenetrable prison she herself built, and uncover the truth before time runs out?
