I was really looking forward for another drama with Kyungsoo, who was really good in his other works. Plus, Bo Gum was an additional bonus, as he can really adapt to his role and he plays the childish roles really well. However, the drama felt a little stiff, as it got stuck into boring plot twists. The background story was interesting; a guy returns to Korea in order to find his brother, who had been kidnapped by their father's killer. However, the drama was almost like a medley of Dexter and the mentalist, with a genius man who ends up working with the police tries to find the serial killer that harmed his family. The killer's shots in the prison were annoyingly repeated over and over in each episode. In addition, the drama was tiring and boring, and the romance was really weak. So, 4 out of 10, only for the good performances of the two actors mentioned.