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.

A vainglorious executive who seemingly has everything faces devastating news when his adept personal assistant announces that she’s decided to quit.

A man who can’t distinguish faces meets a woman who is unforgettable. Lee Yoo Chan is the founder and CEO of the IT company Next One, which has become the most desirable place to work. He suffers from a condition where he can’t recognize faces, and this makes him very guarded and mistrustful of most people. Kim Bo Ra is the pride of her hometown on Jeju Island who came to Seoul to attend college. With her imminent graduation, her dream is to work for Next One. When Bo Ra meets Yoo Chan, will both their lives change in unexpected ways?