In the prequel of Internal Affairs, the assassination of Triad kingpin Kwun in 1991 unleashes a power struggle among other Triad bosses. While they are all geared up to make the first move should the Kwun\'s family collapse into chaos, Sam (Eric Tsang) remains the only loyalist. Meanwhile, the police under the command of Inspectors Wong (Anthony Wong) and SP Luk (Hu Jun) have been placed on the highest alert. A bloodbath is bound to take place.