The Gangster, the Cop, the Devil (2019)

In the wake of a brutal assault from a mysterious serial killer, crime lord Jang Dong-su embarks on an unexpected alliance with Detective Jung Tae-seok, an unlikely duo determined to apprehend the sadistic murderer who goes by the name of K. As their paths intertwine, their once-opposing worlds collide, pushing them to the edge of their abilities. Together, they must defy the norms and delve into the twisted mind of this elusive criminal, their lives hanging in the balance with every step closer to the truth.