Summary
Instead of the Slipspace anomaly at the end of Halo 3 bringing the remains of the Forward Unto Dawn to the Forerunner shield world of Requiem, it brings it to the world of Terra. A year before the events of the Chernobog-Lungmen crisis, it crashes onto the planet. By chance, Rhodes Island would sight its crash and send a squad to investigate it, only to discover its occupants.