Monsters from legends now inhabit the city, which resembles an online game. It was the most ordinary school day until mysterious cards with images of warriors, magicians and archers began to rotate in the air. The students panicked, but not Yu Seon-woo, who unconsciously chose the card and took the path of the necromancer. Now he has a rare ability that gives him the ability to control the undead. While the young man is gaining strength, his enemies are not asleep. With the campus and the outside world on the verge of chaos, Yoo Sung must use his abilities to subdue the monsters and save his friends. But will everyone be able to survive?