1997年4月3日晚10点左右，韩国汉城龙山区梨泰院某快餐店的厕所内，大学生赵宗毕被人残忍杀害，现场惨不忍睹。赵是家中独子，为人谦和礼貌，他的离开给家人以莫大的打击。经过缜密调查，警方最终将目标锁定在现场目击者韩裔美国人皮尔森（张根锡 饰）和美籍韩人亚历克斯（申圣焕 饰）身上。两个桀骜不驯的青年起初否认罪行，接着便相互指责对方才是真正凶手，并各自陈述了完全相反的案件发生经过。负责此案的朴泰锡警官（郑镇荣 饰）费尽心思，却始终无法逼近事实真相，调查陷入胶着状态。一次次审讯，一次次开庭，真正的凶手最终能否现身？ 本片根据真实事件改编。
Gyeong-ah works as a caregiver and lives alone. The only one she can rely on is her daughter, Yeon-su, but it's hard to see her after she moved out on her own. Meanwhile, Yeon-su, who is suffering from her ex-boyfriend, Sang-hyun, argues with him again and visits her mother’s house. After Yeon-su left, Gyeong-ah receives a shocking message from a stranger.
