The drama is a crime action investigation drama that tells the story of the "Outside Black-dog" detective of the serious crime squad who has never let go of a case, the passionate PD of the investigative reporting team who suffers from low ratings, the life-style detective who used to be a profiler, the legendary president of the nuclear explosion who hides his past and runs a bar, and the funeral instructor who was originally an elite autopsy prosecutor of the National Science Search. These five people come together to deal with unsolved cases happily and warmly.