A mother with a heart of gold navigates the cutthroat world of private education when her daughter tries to join a celebrity math instructor's class.

Students in a college cheer squad navigate life, love and relationships, while a series of ominous events keeps them on their toes.

Do Won and Seo Kyung both lose their fathers on the same night 12 years ago. In the present day, Do Won is a police officer and Seo Kyung a prosecutor. The police discover several skeletons on the train tracks at Mukyeong Station, which has been closed for five years. Do Won heads to the station while chasing a key suspect.