The year goes back to the 90s in New York. Peter Robinson, a 32 year old detective has a specific type of personality and a fascination with murderers. His goal as a detective is to understand those that kill. While stumbling across numerous cases to catch a group of serial killers, he's told by all kinds of murderers that he may not be so different from those that take lives after all, which makes him question his believes. While being used to working alone, he suddenly gets teamed up with 34 year old detective Stanley Nelson, which Peter can not stand. The two men are very different from each other and don't get along, but have to do their best at working together to catch the mysterious killers that have been providing terror on New York city grounds.