After nine college students are trapped under a collapsed building for 14 days, only six come out alive, and only four of them can speak. The dead bodies of their fellow students are viciously mangled, leading police to investigate the case as a possible homicide. Detective Lieutenants Jeongdo Kwon and Yeongchae Shin, together with renowned neuropsychiatrist Dr. Yeongwha Ju, must parse through witness testimony and inconclusive physical evidence to uncover the truth. But how do you solve a locked-room murder case when every witness is a suspect?