The Human-Covenant War, a desperate struggle for humankindś very survival, has reached its boiling point on the mysterious, ring world called Halo. But the fierce Covenant warriors, the mightiest alien military force known, are not the only peril lying in wait. As the fortress world of Reach and its brave defenders were bombarded to rubble, a single cruiser fled the carnage with the battleś only human survivors-Captain Keyes, his crew of a few hundred Marines, and the last remaining SPARTAN super-soldier, the Master Chief. With the cruiserś artificial intelligence, Cortana, concealed in his battle armor, the Master Chief crash lands on Halo in the midst of a massive Covenant occupation. Curiously, the alien soldiers appear to be searching for something hidden on the ring. Built by a long-dead race, Halo harbors many deadly secrets, but one overshadows them all. Now the Master Chief must lead the scattered troops in a brutal race to unravel Haloś darkest mystery̮and unleash its greatest source of power.