A Dirty Carnival (2006)

Kim Byung-doo, a low-level criminal, is far from becoming a professional gangster. Dangerous and ambitious in equal doses, Byung-doo is willing to go to great lengths to rise through the ranks of his boss Sang-chul's organisation; however, he still hasn't earned it. Desperate for cash, while unable to take care of his family, eventually, Byung-doo seizes his golden opportunity to impress the big boss and accepts to do away with a greedy public prosecutor who knew too much. Nevertheless, every promotion has a price, and nothing is what it seems in the cruel realm of the violent criminal underworld. And before long, Byung-doo will discover the dirty truth in an already dangerous game.