At four o'clock in the morning, the sound of brooms in the dilapidated boxing gym hid the shadow of the former boxing champion. Retired special forces soldier Zhou Ye was chased for debts in an underground boxing ring. He mistakenly broke into the forbidden area, but was punched three meters away by the old sweeper Chen Shoushan. One wanted to regain his fighting spirit, and the other wanted to clear his reputation. The two formed a master-disciple contract beside the simple boxing ring. The female boss Qin Shuang desperately defends the boxing gym, the underworld boss Zhao Heting is pressing harder, Coach Tieniu has a recurrence of an old injury, and the rehabilitation specialist Su Yue is secretly dealing with the situation. The master and apprentice not only have to win the ring, but also uncover the dark truth about twenty years ago. The fist is hard and the heart is warm. On this road to comeback, every punch must be paid for with life.
