Jiang Jiu, the legendary Ninth Master of the underworld, announces her retirement on the night she reaches the top because she is pregnant. But her most trusted brother, Hu Zhenshan, knocks her unconscious with a club and imprisons her in a secret chamber for twenty years. She carves 7,300 tally marks into the wall, listening as her daughter is beaten every day on the other side. Then one day, when her daughter cries out, "If I really had a mom," the hidden door shatters, and her shackled, barefoot feet emerge from the chamber. She cuts off her long hair with a single slash and knocks down a special operations team with one punch. Men in black suits throughout the building kneel and shout in unison, "Ninth Master!" After twenty years of imprisonment, she is ready to reclaim, with interest, everything that belongs to her daughter!