The Covenant Assault Force

above planet Reach, as the humans fights the Covenant assault forces. The last defense for the planet is an array of MAC guns orbiting the planet. The Master Chief sends a squad of Spartans to the surface of Reach to protect the MAC's generators. Eventually , the Covenant are able to destroy the generators and begun glassing reach destroying everything at the surface and turning it to glass. The remaining Spartans flee underground to the secret headquarters of the ONI. There they meet Dr. Halsey (the creator of the SPARTAN II’s ) who, with help of some of the surviving Spartans, uncovers a strange crystal shard in a cavern built by the Forerunner. Pursued by the Covenant, the Spartans retrieve the crystal and the cave collapses behind them, which saves them from the chasing Covenant forces, but also traps them deep under the surface of
Locklear decides to destroy the crystal, inadvertently killing himself, but stopping the Covenant from tracking the crystal's radioactive signal and the Ascendant Justice. With the knowledge that the Covenant are en route to Earth, the Master Chief and his fellow Spartans decide to disrupt the invasion force at their rendezvous point. The Spartans successfully infiltrate the Covenant space station, Unyielding Hierophant, set it to self-destruct and escape in a drop-ship. On board the Ascendant Justice, Whitcomb tricks the Covenant fleet into following the ship closer to the Unyielding Heirophant; when the station explodes the entire Covenant fleet is destroyed or damaged. Master Chief and the surviving Spartans take the salvaged UNSC ship, back to Earth with Sgt. Johnson and Cortana to warn of the coming invasion. In the meanwhile , the Covenant leadership discuss the fate of the heretic , an Elite who allowed Halo to be destroyed and the Ascendant Justice to be