A group of unhappy strangers decide to end their lives together, but soon they find that their plan is flawed after one of them turns out to be a beautiful woman.
Ancient Korea, 1506. The tyrannical King Yeonsan-gun of Joseon is overthrown by his half-brother Jung-jong, whose reign begins with a blood bath. Over the years, traitors plot against him, sinking the kingdom into chaos. In 1528, frightened rumors come to royal palace, regarding a mysterious creature, known as Monstrum by the peasants.
Ancient Korea, 1728. Swordsman Kim Ho, guard of King Yeong-jo of Joseon, is demoted and sent to work in Uigeumbu prison. When night falls, the prison is assaulted by the master warrior Do Man-cheol and his powerful henchmen for the purpose of freeing Lee In-jwa, who has been condemned to death for rising up in revolt against the king.
Dong-hyeon and Yong-joon coincidentally meet at an acting audition. A strange gentleman appears in front of the both of them who are sick of failing at these auditions and suggests something to them. Meanwhile, Ayaka comes to Korea with her best friend Saori to meet her fiancé, Min-joon's parents. She runs into Dong-hyeon and Yong-joon who ask her to star in something and although she's not up for it, she's ushered into doing it by Shiori who loves handsome men. They move locations to a run-down facility and suddenly all exits are blocked and the four of them are trapped. Ayaka looks for an exit but instead finds cameras put up everywhere and gets the feeling that they are being watched. She suspects Yong-joon and Dong-hyeon of being behind this.