While the brutal Covenant juggernaut sweeps inexorably through space, intent on wiping out humankind, only one stronghold remains - the planet Reach. Practically on Earth’s doorstep, it is the last military fortress to defy the alien onslaught. But Reach’s defenders have another, higher priority: to prevent the Covenant from discovering the location of Earth.
Outnumbered and outgunned, the soldiers seem to have little chance against the Covenant, but Reach holds a closely guarded secret. It is the training ground for the very first super soldiers. Code-named SPARTANs, these highly advanced warriors, specially bioengineered and technologically augmented, are the best in the universe - quiet, professional, and deadly.