Lee Do confronts a violent standoff and must decide how far to go to stop the killings, while suspicions about Moon Baek threaten their fragile alliance.
Guns reach bullied students and grieving parents, sparking new tragedies. Lee Do uncovers a network delivering weapons to vulnerable people across Korea.
Un alumno armado provoca una crisis en el colegio. Lee Do y Moon Baek se apresuran a restablecer el orden mientras crece el pánico, pero quizá sea tarde.