Cheng Bing (played by Zhang Yi), the captain of the Criminal Investigation Brigade, caused the accidental death of a suspect in the process of handling a criminal case by the Third Brigade and was sentenced to prison. After being released from prison, he still insisted on tracking fugitive suspects as ordinary people. The film is adapted from real events and was originally published in "Please tell the Director, the mission of the Third Brigade has been completed" by Shenlan, the author of "NetEase Human World Studio".