With their 15-year-old son about to be sentenced for robbery, his family approaches the judge's lawyer with a bribe to reduce the charge. Unknown to the family, the attorney keeps the money and Zhang Shuai is sentenced to three years in jail.
Released from prison and consumed by hatred after learning his mother dies as a result of selling her kidney to get the bribe money, Zhang vows to find evidence that the judge, An Hui, accepted the bribe and vows to send her to prison. Establishing himself as An Hui's houseguest, Zhang carries out his plan and brings her before the prosecutor, where she is cleared of the charge.
While celebrating his 18th birthday, a long forgotten letter appears, revealing the true facts and exonerating An Hui, allowing Zhang to understand the important part that An Hui played in his life.