On the night of March 14th, 2001, exactly one day after the incident at Yeondu High, four individuals return to the school in search of answers to the unresolved mysteries that plague them.
Episode 1: Troubled by rumors of her involvement in a fellow student’s death, Jung Soo-jin is determined to set the record straight and win back the trust of her crush, Jang Sung-tae. But as the pair search for clues, they learn of a far darker secret hidden deep within the school’s bowels and become the prey in a relentless hunt.
Episode 2: At the very same time, former trainee teacher Kang Seo-yeon arrives to investigate the ambiguous circumstances surrounding her father’s death in the school grounds. Drawing on her knowledge of the occult, Seo-yeon attempts to reverse an ancient ritual while evading a powerful and evil ghost that is inexorably drawn to her.
Episode 3: Having made a promise that cannot be broken, freshman student Yoo Ji-min searches for a way to bring peace to the restless spirit of Han Na-young. Delving deeper into the school’s tragic history and the complex relationships among its students, Ji-min makes a fatal discovery that will lift the veil of darkness once and for all.
