At about 10:00 on the evening of April 3, college student Zhao Zongbi was brutally killed in the toilet of a fast food restaurant in Ritaiyuan, Longshan District, Seoul, South Korea. Zhao is the only child in the family. He is modest and polite. His departure is a great blow to the family. After careful investigation, the police finally targeted the eyewitnesses at the scene, Korean-American Pearson (Jang Genxi) and Korean-American Alex (Shen Seung-hwan). The two recalcitrant youths at first denied the crime, then blamed each other for the real killer, and each told the exact opposite story. Park Tae-suk, the police officer in charge of the case (Zheng Zhenrong), tried his best, but he was unable to approach the truth all the time, and the investigation fell into a tight state. Trial after trial, trial after trial, can the real killer finally show up? This film is based on real events.