Decoy - the criminal male lead ran a pyramid scheme that led to a man setting himself on fire and suicide of at least one other victim. It also caused one of the victims to start revenge killing some of the criminals involved.
Maybe I'm in the minority but I didn't enjoy the ending. The main rivalry.
Hooking up two people to wires and a computer and making them watch videos and images of distressed people while there is a video of their loved ones in danger being live telecasted on the screen next to that is a bit of a mess to begin with. The only believable part was when Ha Ru actually saw his friend pass out and he felt sad. But the graphics and set up was terrible. Then the female Detective walking in to the trap when both men are shaking their heads and no one calling for backup during this whole process. Hwang Dong Woo could have easily stabbed Myung Se with the syringe or even Ha Ru when he turned his back on him. This whole part felt so weak.