Major Crimes captain Park Kang-yoon receives special funding to carry out his investigations and lives the life of luxury with fancy sedan, high-end condo, designer suits and accessories. A rookie named Min-jae joins his unit, who happens to be very by the book. The pair becomes close as they begin investigating a new type of street drug, but Kang-yoon finds out that there is a mole within his unit, who has been compiling a case against him.