Cha Do Hyun is a rich heir to a family company with one major problem. Due to suppressed childhood trauma, he suffers from dissociative identity disorder manifested in 7 unique personalities who are out of his control. In order to overcome this disorder in secret, he hires a first year medical resident to help him heal by killing off each personality one by one.

Yoo Seol-Ok liked mystery novels and wanted to become a detective, but she gave up her dream after marrying. Now, she is a housewife with a husband who works as a prosecutor. She meets Ha Wan-Seung. He is a passionate detective and they decide to collaborate to solve cases.

Set during the Goryeo dynasty, Won, crown prince, has a sweet appearance hiding a lust for conquest. He is best friends with Rin, an elegant man of royal descent and Won's bodyguard. When beautiful San, the sole daughter of the wealthiest man in the nation, enters the lives of the two young men, the three at first become friends but a tragic romance ensues afterwards. Based on the novel of the same name by Kim Yi-Ryung.

A crew, drilling offshore for oil south of Jeju island, finds a lethal alien life form instead.