In a big city of Busan, twin brothers were left in the orphanage after the tragic death of their parents. Taeju, the older brother, becomes a cop and Taesung, the younger one, holds a significant position in the local gang. Their ironic fate adds up to have both of them love the same girl, Chanmi. As the feud between two different gangs surrounding the casino heats up, Taesung’s best friend betrays him and places him in a trap. As police line approaches, Taeju comes to persuade Taesung to surrender but first they have to face the truth about the traumatic incident which caused them to drift apart.