Paris, the 1980s. Three students decide to celebrate their graduation with a visit of the Paris catacombs. But something, someone, is hunting them. Trapped deep underground, the group needs to get out before it's too late...。屡次遭遇求职失败的青年朴正九(卞耀汉饰),唯一的才能就是制作炸弹。一天,知道如何引爆炸弹的孝民(朴正珉饰)出现在朴正九面前,二人成为了绝佳拍档。而与表面上平凡普通、顺应社会的朴正九不同,孝民一旦“开始”便无法停下…...。