- last post: 01.01.0001 12:00 AM PDT
Or maybe if some of the Forerunners were freaked out about the Halo destroying their entire civilization, so they hid in their own built shelters to protect them. After the Halo was activated they came out and were consumed by the flood. Now in the future Gravemind controls them and sends them to Earth along with the Covenant/Flood armada to fight Earth, the Covenant, and the remaining Spartans.