Lee Dong-sik was once a capable detective. He is demoted to working at Manyang Police Substation, where he does all the mundane chores. His peaceful life is interrupted by Detective Han Joo-won, who arrives as his new superior. Han Joo-won is an elite detective with high social standing, but he harbors a secret. When a series of gruesome murders wrecks the quiet city, Dong-sik and Joo-won team up to catch the culprit.