Karlovy Vary is a beautiful city located in the western Czech Republic. Sung-Jae, the director of the film, completed the script with Karlovy Vary in mind, and his work received awards for various contests and even got investment for the film production! Sung-Jae accomplished everything he dreamed of at once. After finishing filming on the domestic set, now he only has to film in Karlovy Vary. However… all the invested production money is gone! In order not to cough up the money, Sung-Jae has to finish the movie no matter what! Will Sung-Jae and his friends be able to finish the movie without going to Karlovy Vary?

婚期将近的高中教师书邻（李宥英 饰），收到来自大家的祝贺礼物，在她喝下办公桌上的咖啡后，随即陷入了昏睡，直到隔日清晨才被学生唤醒，从此她宁静的生活一去不复返。不久，书邻的手机收到一封来自「Master」 的恐怖骚扰讯息，内容竟是自 己不省人事时的照片，更令她不寒而慄 的是，这一切彷彿是14年前相同的噩梦重演。 书邻找来前刑警国哲（金希沅 饰）一起追查案件真相，希望能找出幕后黑手「Master」。此时，书邻班上的学生们也开始收到「Master」的骚扰讯息，事件主角变成是班上的一名女学生。侦办过类似案件的国哲也直觉不对劲，当情况越来越诡谲，究竟两起案件的关联与牵扯为何？而隐身在黑暗中操控一切的「Master」到底是谁呢？