Often called a cruel film, I think its misfortune is mistaken for heartlessness. But the film holds sympathy for each protagonist in its tragedy and gives each of them ample screentime to explain how we got here, and that makes the wave of violence that envelops the final third well earned. It didn't- shouldn't- have to be this way. One scene in particular solidified this for me; the detective needing ten million won, in the same scene where Dong-jin mentions the economy crashing. Societal ills created this situation and thrust it forward, and the fact that these three would've been good people otherwise is the heart of the tragedy.

"I know you're a good guy... so you know why I have to kill you..."

The film views them all as human, all have the capability of being good at their heart. But inversely, human nature compels them forward to continue the cycle.I think the film is also buoyed by knowing when to show the brutality and when to pull back, knowing which will make the viewers wince to see and which will be even more brutal for them to imagine. Add in a killer cast, especially Song Kang-ho and Bae Doona, and it's a film you shouldn't miss.