The Flood are Precursors. The survivors took form as dust that could later regenerate itself. Laying dormant for so long, the dust became diseased and rotten. Yet, the others saw this as a golden opportunity. They also declared themselves as "legion."

The Forerunners who chased down the Precursors in other galaxies were not without internal strife. Many could not bear the shame of returning to Orion after exterminating their creators. Abandoning their great expeditionary fleet, they secluded themselves to a simple planet with little in the way of natural resources. These martyrs did on the other hand create an organic Domain risiding within all of the planet's organic life. The Librarian was implanted, through an old woman's bite, with a geas-like connection to these people's history, culture, and language. Audacity returned to Orion hundreds of years before Ur's release on Earth.