A mysterious youth drama begins when a class of second-year high school students is suddenly forced to play mafia games in real life while on a retreat. The drama will reveal the intense psychological battle among students as they enter survival mode. The students of Class 3, Year 2 at Yooil High School go on a school trip. There, they are compelled to participate in a deadly mafia game and must fight to survive. Lee Yoon Seo possesses exceptional observation and reasoning skills that she uses to try to escape. Kim Jun Hee is the class president with a strong sense of justice and responsibility. Oh Jung Won is academically the top student, but is an outcast and lonely. She must work together with the other students to survive.
