Shen Yi (played by Tan Jianci) first joined the Criminal Investigation Detachment of Beijiang Branch as a mock portraitist, and was arranged by the leader to partner with the captain of the criminal police, Du Cheng (played by Jin Shijia), to handle the case. Du Cheng's initial provocations established the history of the relationship between the two. With the development of the subsequent plot, the close cooperation between the two pushed the confrontation between the characters to a climax. The compact plot, the flashing portraits, and the confusing clues of the case seem to tell the hidden truths and untold stories.