My Perfect Stranger Episode 4

With the day drawing closer, Hae Jun experiences mounting anxiety over the possibility of failing to prevent the murder, given his limited information and unexpected developments. While the school is on a field trip, a new student teacher is introduced, whom Yun Yeong finds strangely familiar. Later that night, while alone at home, Yun Yeong recalls the true identity of the student teacher. (Source: Viu)