The Mathematics Teacher (S01E09)

Title: The Mathematics Teacher Plot: While Su A heals in the hospital after the break-in incident, Hae Seong and his team discover that the perpetrator is none other than Lee Jun Ho, the math instructor. When Hae Seong notices his father's notebook is gone, it dawns on him that Seo Myeong Ju was behind the break-in. After Lee Jun Ho is taken into custody and admits his guilt, the shocking revelation of a grade manipulation scheme sends the school into disarray. In the midst of this chaos, Hae Seong uncovers a vital clue related to the final eerie tale.