Mu Yeom makes a false confession to the 2nd murder for ulterior purposes, but some inconsistencies have Chul Gon starting to believe they may have similar motivations. Chul Gon and Mu Yeom enter into a grudging collaboration, and Chul Gon makes a sacrifice to help Mu Yeom enter the jail clinic to search for the real Gap Dong. Tae Oh's collaboration with Gap Dong is revealed as the 3rd murder is strategically executed with ulterior purposes. The date of the 4th murder draws near.