One night, Yi-Na’s uncle, who was like a father, mother and friend to her, was murdered. She was the only witness of her uncle’s murder case. She was also suspected as the murderer by Han-Saem. 10 years later, Yi-Na now works as a criminal profiler. She has been a member of the criminal analysis team at Seoul Metropolitan Police Agency for the past 6 years. Yi-Na is usually the first to figure out the motive of a crime from the crime scene. Yi-Na now meets Han-Saem, who was convinced that she killed her uncle. They work together to uncover the truth behind the murder.