Doctor Lee Joo-yeon's past was revealed. She had been seriously injured, an experience that left her unable to truly shake off her fear.Her relationship with Yin Zhengmin seemed to be peaceful, but the wounds were torn open again by old sins.At the same time, the clues to Kim Beom-joon and Park Jae-young's identities become more confusing, and the boundaries between survivors, imposters and hunted people begin to flip.