Sun-woo and Se-ra visit the school he attended 20 years ago in search of Kim Nam-gyu's whereabouts and hear unexpected names there. On the other hand, Se-ra is confused by the mysterious memories that comes to her mind as she gets closer to Sun-woo's incident. Sun-woo, who finds out that Vice Chairman Kang was the real culprit with Jae-ha's help, immediately comes into Wan-soo's house, but faces Vice Chairman Kang, who is unconscious and has a suicide note left.
