Wei Wuxian, boss of the criminal organisation Burial Mounds gets sentenced to death after the murder of Nie Mingjue, Jin Zixuan and Jiang Yanli. Full of doubts, Detective Lan Wangji finds their older friends Shen Qingqiu and Hua Cheng, to help him investigate the case, involving corruption, crimes and intouchable people. Shen Qingqiu and Hua Cheng are then forced to face their past mistakes and memories to help their dear best friend.