When an old collaborator gets severely injured, a veteran policeman tries to figure out the way to bring to justice the ultimately suspected aggressor, a spoiled young executive, heir to a mega corporation, who believes he is above the law.

The veteran detective Seo Do-cheol and his team at Major Crimes, relentless in their pursuit of criminals, join forces with rookie cop Park Sun-woo to track down a serial killer who has plunged the nation into turmoil.