This drama is really interesting. But really hard to keep up with. this show will show you the best PSYCHOPATH and MANIACS there is. so many strategies and killing chains. like one killing after another all by GAPDONG. it really makes you want to follow the clues that they give you. and trust me you start to suspect everyone that is involved in the GAPDONG case. form the past all the way to the present. You meet mental hospital [patients, survivors, and killers. follow the patterns of the killings if you want to find out who started all of this. There are a lot of secrets revealed, Must watch until the end to understand everything. Trust me. so many people in the drama that you have to keep up with. Mostly killing, and action.