
This drama is a romantic thriller that centers around a criminal profiler, Lee Hyun who previously work as a consultant at the police department in New York. After he returns to south Korea, he’s in charge of a special criminal investigation team. Due to his special insight, he can analyze the crime scene and the suspect at one glance. He works together with an elite detective, Cha Ji An to solve the crimes and they develop a romantic relationship.

Lee Hyun, a Criminologist working for the New York Police, returns to Korea to investigate a recent email that he received. He hopes to recover all of his early memories that he lost after the tragic murder of his father. On arrival at the airport, he deciphers some cryptographic symbology that leads him to a recent murder scene. Team 1 Investigative Unit arrives while he is there and mistakes him for the new Team Leader. However, Cha Ji-An, the Lead Investigator knows who he is because she has stalked him since her youth.

Plagued by insidious thoughts planted by serial killer Lee Joon-Yeong and recent events; Lee Hyun's father believes that he is becoming a monster. He isolates him in the basement to protect both him and the world. Joon-Yeong escapes from prison, murders his father and absconds with his brother. Lee Hyun discovers a painting at a murder scene that he believes may be his brother Lee Min’s.

Team 1 working with Lee Hyun come up with a profile of the victims. Cha Ji-An races to the next suspected victim and is successful in capturing the murder suspect but complications arise as there is no proof and the target drops any charges. Attorney Jung Sun-ho arrived during the interrogation process and thwarts Lee Hyun and Cha Ji-An efforts to get a confession.

The murder suspect, Yang Seung-Hoon, leaves on the first available plane to China. Lee Hyun illegally uses Cha Ji-An’s computer and informs Chinese authorities of his drug trafficking. They find evidence at his house and arrest him on arrival. Team Leader Kang Eun-Hyuk and Planning Officer Hyun Ji-Soo are reprimanded by the Deputy Chief for mishandling the case. Cha Ji-An is transferred to another department. Detective Yang sets up a meeting with Lee Hyun to relay some pertinent information concerning Joon-Ho. Detective Yang is murdered, and he becomes the prime suspect.

Cha Ji-An is going stir crazy wanting to investigate so she joins up with Lee Hyun. They evade capture by hiding in a closet at the crime scene. They start bonding while he hides out at her place, and she attends his wounds. He convinces her to spy for him. Together they are able to figure out who the murderer is and his next target. The Team Leader, Kang Eun-Hyuk, makes the arrest. He and the Planning officer convince the Deputy Chief to return Cha Ji-An to the team.

Lee Hyun meets with Prosecutor Shin Jang-Ho concerning Park Young-Chul's case. Jang-Ho informs Lee Hyun has experienced two cases of memory loss in relationship to his parents' deaths. Also, that Lee Joon-Yeong never leaves any bodies to be found for his murder cases. In order to investigate the Park Jeung-Woo murder case, Lee Hyun is coerced to join Team 1 as an official advisor. Lee Hyun hires Jung-Sun-ho to be Lee Jung-Ha’s attorney because he believes he is innocent.

Lee Hyun confronts Cha Ji-An about her doubting him and thinking he may be like Lee Joon-Yeong. Lee Hyun believes Lee Jung-Ha is covering for Lee Jin-Woo. Teams 1 solves the Park Jeung-Woo murder case. After doing some soul searching, Cha Ji-An comes to the conclusion that she is wrong, and Lee Hyun is not like Lee Joon-Yeong. She tells him that he is weird and annoying but not a monster. After solidifying their partnership, she asks him out on a date and takes him to a closed amusement park to spend time together.

Chi Ji-An is brutally attacked in her home and Attorney Jung comes to her rescue. Lee Hyun finds it suspicious and questions him if Yang Seung-Hoon is behind the attack. After her hospitalization, Lee Hyun decides to let her stay with him for a few days. Ji-An is awakened from her sleep to find Lee Hung at his desk having nightmares. When Lee Hyun checks back with his Art Gallery friend, Na Bong Sun, finds out the symbol on the paintings is linked to an employee at the Fako Shipyard. Going undercover, he discovers another dead body.

The Planning Officer still refuses to open up to Lee Hyun concerning his past in regard to Joon-Young. Team 1 starts working on another serial killer case involving stalking and missing persons. Detective Son’s blind date, Ji Hyun-Sook, goes missing. Lee Hyun develops a profile with possible locations the culprit may be working from. While Cha Ji-An and Team Leader Kang go to check it out, Lee Hyun has a dinner date with two persons of interest to him, Attorney Jung and Pathologist Lee.

The serial killers, Do Jae-Shik and Kang Seong-Eun, capture Cha Ji-An and leave Team Leader Kang dying from a knife wound. Lee Hyun, Attorney Jung, and Pathologist Lee join Team 1 as they rush to apprehend the suspects. Planning Officer Hyun finally confesses about her deal with Joon-Yeong that inadvertently lead to the death of his father and his brother’s disappearance. Officer Cha and Ji Hyun-Sook are rescued. Budding romance blooms as Lee Hyun and Ji-An move closer in their relationship.
Available on: KBS2