Bent on Humankind's extermination, a powerful fellowship of alien races known as the Covenant is wiping out the Earth's fledgling interstellar empire. You and the other surviving defenders of a devastated colony-world make a desperate attempt to lure the alien fleet away from Earth. Shot down and marooned on the ancient ring-world Halo, you begin a guerilla-war against the Covenant. Fight for humanity against an alien onslaught as you race to uncover the mysteries of Halo. Halo takes you deep into the far future, with the future of planet Earth hanging on your shooting skills! After a massive battle, only one ship is left, its crew stranded on an abandoned space station. You must do whatever it takes to keep the Covenant from reaching Earth.