A TV series centered around the unfolding relationship between free and unpredictable yet dangerous Kim Moo Young, who is called a "monster". He is the first assistant in a Korean beer brewery who becomes a suspect when a woman's suicide turns out to be murder. His life begins to change when he meets a kind, warm advertising designer named Yoo Jin Kang, who wishes to be Moo Young's safe haven. She bears as many emotional scars as him. Yoo Jin Kang also has a brother, a homicide detective named Yoo Jin Gook, with 27 years of job experience. He strives to "reveal" who Moo Young really is and attempts to keep his sister, Jin Kang, away from Moo Young, with whom she begins to know.
Will a killer-turned-veterinarian and a detective find common ground? Kim Soo Hyun is a veterinarian who is also a professional killer. Many individuals and organizations hire him for large sums of money. Nobody in the public knows anything about him as a killer, including his age, name, and race. Animals are his only companions, but deep inside, he constantly yearns for love. He struggles to develop and maintain any pure relationships around him. One day, a client asks him to kill in exchange for information regarding his mysterious past and a conspiracy involving his birth. Do Hyun Jin was once a ballerina, but now she is a detective working in Seoul, who graduated from the police academy as the most excelled. Although she looks cold and stern on the outside, she is, in fact, a very sympathetic individual. Hyun Jin trusts her instincts and isn't afraid to rely on the things around her to make a decision to the best of her abilities. She has suffered trauma but still keeps pushing forward. She starts to chase after Kim Soo Hyun as she believes he is a serial killer. What happens when both get to know that the connection between them has started years ago?
Lee Ra El was a girl who idolized her loving parents – a highly intelligent father and a strikingly beautiful mother. But when cruel forces beyond their control cause her father’s death, her family crumbles. Embittered by this terrible experience, she vows revenge on the super-rich people who orchestrated this terrible tragedy. Her prime target is Kang Yoon Kyum, the CEO of the lucrative LY Group business empire, and one of the ringleaders of the plot that ultimately destroyed her family. Lee Ra El’s weapon of choice is divorce. By placing herself at the center of a legal battle worth a staggering USD 1.6 billion, she hopes to bring Kang Yoon Kyum and LY Group down once and for all. But in order to do so, she will need to wage a bitter legal struggle and fight powerful forces both inside and outside the courtroom. However, this plan has been in the pipelines for 13 years for Lee Ra El, who believes she will use all of her guile to catch Kang Yoon Kyum out when he least expects it. Can revenge bring her the satisfaction she craves – or will it end up consuming her?
