Jo I-na finds her uncle murdered beside a puzzle piece but can't explain her presence. Ten years later, as a criminal profiler, she investigates murders where victims are found with similar puzzle pieces.

Detective Ma Seok-do joins the Cyber Investigation Team to nab Baek Chang-ki, a former mercenary and the head of an online gambling organization.

Seven years after the roundup in Vietnam, Ma Seok-do joins a new squad to investigate a murder case. He soon starts to dig deeper when he finds out the case involves a synthetic drug and a gang of thugs.

Will tell stories of emotional love and breakups. Ha Young-eun, a manager of the design team at a fashion label who is a trendy and intelligent realist. Yoon Jae-guk, a wealthy and popular freelancer photographer who also has the brains and looks. Hwang Chi-sook is a director of the fashion label’s design team who attended high school with Ha Young-eun and Seok Do-hoon is a skilled PR company CEO.