Jung Tae Suk (Kim Mu Yeol) is a police officer who is dispatched to the scene of a bloody murder: After two cars collide, one of the motorists brutally kills the other.
This same killer attempts to strike again when his car hits a vehicle being driven by mob boss Jang Dong Soo (Ma Dong Seok). But the gangster manages to fight back against his attacker, although the fight leaves him badly injured.
Jang Dong Soo assumes the incident was part of a plot to kill him, hatched by a rival gang. He orders his henchmen to mobilize.
But Jung Tae Suk comes up with a surprising and unconventional plan. He shows Jang Dong Soo that a devious serial killer is the real perpetrator – and asks Jang Dong Soo to help him bring the villain to justice.
Jang Dong Soo agrees, but only on the condition that if he catches the killer first, he will be free to administer his own form of justice.
Can this unlikely pair catch the killer in time to make the murders stop?
“The Gangster, The Cop, The Devil” is a 2019 South Korean thriller movie directed by Lee Won Tae.