Bungie.net's About Halo 3 page says this: Halo 3 is the third game in the Halo Trilogy and will provide the thrilling conclusion to the events begun in Halo: Combat Evolved. Halo 3 was first revealed at the Electronic Entertainment Expo in Los Angeles on May 6th, 2006. Halo 3 will be available for Xbox 360 in 2007. Halo 3 will pick up where Halo 2 left off. The Master Chief is returning to Earth to finish the fight. The Covenant occupation of Earth has uncovered a massive and ancient object beneath the African sands - an object who's secrets have yet to be revealed. Earth's forces are battered and beaten. The Master Chief's AI companion Cortana is still trapped in the clutches of the Gravemind - a horrifying Flood intelligence, and a civil war is raging in the heart of the Covenant. This is how the world ends...