Cleverly building up on the plot of the first two movies Infernal Affairs 3 focuses on the efforts of undercover triad-mole cum police inspector Ming''s attempts to become a good cop. He is the only one of the five moles alive. And yet when tapes which Yan had recorded resurface Ming''s position in the police force is at stake. His task at hand is to plot someone as a mole and clear his own name. But the past comes back to haunt him and his journey to become a good cop will not be without its twist and surprises.