Ming is a sergeant in the Hong Kong police force, but his true colours lie with his Triad boss; Yan works for the same Triad boss but his real loyalties are with the police. Both men have spent years leading the same furtive and often fraught existence but for opposing sides, and it is only when a drugs bust goes spectacularly wrong that the two moles become aware of the other's existence, though not their identity. Infernal Affairs is a hard boiled character driven thriller that concentrates heavily on the inner turmoil, desperation and disillusionment of Ming and Yan to great effect. An intelligent and gripping piece of populist Hong Kong cinema.