Jae Kyung puts the puzzle pieces together of the day Jun Seo died, and a rift between Jong Soo, Tae Jin, and Ji Yeon pushes them apart. Meanwhile, Jae Kyung, Yun Jin, and Joo Song visit Hyun Woo, discover the whole story between Jun Seo and the medication incident, and then find a clue to the murder at the mill.