[quote][b]Posted by:[/b] halo odst 117 MC [quote][b]Posted by:[/b] Cmdr DaeFaron Wasn't the cure not destroyed, along with all knowledge of how to create it? Thus the flood didn't adapt, it merely had nothing to hold it back again.[/quote] I thought this too.[/quote] Primordium reveals that there was no cure, the Precursors merely chose to pull the Flood back on account of deeming us worthy (after we sacrificed so much). The attemted cure itself never worked.