In the early 1990s, undercover Xing Ling sent by the Public Security Bureau of Hajiang City in Northeast China was unfortunately killed because his identity as an undercover agent was exposed. Xing Jing, who was studying criminal psychology at Qingbei University, was devastated when he learned that his father, who was an undercover agent, died. He made a solemn oath in front of his father's grave: After graduation, he would return to Hajiang, inherit his father's unfinished police career, bring his father's murderer to justice, and continue to protect this land.
As time went by, Xing Jing returned from his studies and emerged in the Northeast police circle with his professional criminal investigation knowledge and methods. In the next thirty years, he would work as a police officer and go to the scenes of serious crimes. Xing Jing engages in various thrilling games with moles and criminal groups in the police force, and persists in fighting all kinds of serious and strange cases to the end. Behind this is his persistence in justice. The smooth detection of each serious case and the successful identification of the mole of the year are a powerful counterattack against the evil forces. He uses his legendary police career to explain the mission of a criminal police officer.
