Su Huimin handed her salary passbook to her mother-in-law Liu Guilan, outwardly submissive, but actually only handing over the basic salary according to factory rules while bonuses were settled separately. The mother-in-law managed the household harshly, locking the refrigerator, scrimping on meals, and secretly remitting money to her lover Xu Defa. Her husband Zhao Yongqiang was weak and blindly filial, handing his salary to his mother and relying on his wife for expenses, and cheated with Li Lian during a business trip while getting blackmailed. Step by step, Su Huimin recorded audio and took photos as evidence, exposing backdated false IOUs, sham debts, and the truth of money transfers, finally reporting to the police, getting a divorce, taking back her passbook, and retaking control of her life. A game of chess between a mother-in-law and daughter-in-law centered around a salary passbook, peeling back marital calculations and betrayal.