A Hard Day

Ko, a corrupt detective, grapples with the grief of losing his mother. The funeral serves as a backdrop to the turmoil in his life as he faces investigation by internal affairs for bribery.

While driving away from the funeral, Ko accidentally hits and kills a homeless man with his car. Overwhelmed by the fear of facing manslaughter charges due to his intoxication, Ko decides to hide the incident instead of reporting it.

In a panic, Ko places the body of the homeless man in his car trunk, narrowly avoiding detection by a passing patrol car. He then makes a chilling decision to hide the body inside his mother's coffin.

After the funeral, Ko discovers that the man's cell phone was left behind in the coffin. This revelation increases the tension surrounding his already precarious situation.

The squad is assigned to track down a murderer named Lee, who is later revealed to be the same homeless man Ko killed. The investigations intensify as they search for clues related to Lee's whereabouts.

As the police investigate, they stumble upon a traffic camera footage that captures the collision. The resemblance of Ko's vehicle to the car in the footage raises suspicions about Ko's involvement.

The triangulation of Lee's cell phone suggests his activity near Ko's mother's grave, further linking him to the case. This new evidence puts Ko on edge as the investigation narrows in on him.

Ko learns that Lieutenant Park, who witnessed the collision, chooses to blackmail him rather than report him. This revelation complicates Ko's moral crisis as he finds himself ensnared in a web of deceit.

In a desperate attempt to understand the situation, Ko digs up his mother's coffin. He discovers that the homeless man had bullet wounds, indicating that his death was not just a tragic accident.

Ko tracks down a criminal who reveals details about a significant theft of cocaine linked to Lieutenant Park. The criminal identifies that the homeless man stole a key to a vault before being shot, deepening the intrigue.

Frantically, Ko returns to the grave site to search for the key to the vault. However, he is confronted by his own subordinate, who has been investigating the damage to Ko’s vehicle.

Things take a dark turn when Park resorts to using lethal measures, crushing Ko's subordinate's car. This brutal act ensures that the weight of Ko's actions remains undisclosed.

Feeling trapped, Ko devises a plan to save his family. He prepares an explosive device and places it within Lee's body, intending to leverage it against Park for his own safety.

In a shocking moment, Ko presents the corpse to Park, triggering the explosion that sends Park's vehicle off a bridge. This dramatic act marks a turning point, showcasing the desperation and chaos in Ko's life.

After the chaos, Ko confronts Park, who unexpectedly survives the blast. In the ensuing struggle, Park accidentally shoots himself. Eventually, Ko uses the key from Lee's body to unlock Park’s vault, revealing a hidden cache of cash.