Jillybean has posted a small update to the Halo Story Page. I don’t particularly agree with the theory presented, i.e. that the Halos work by teleporting the Flood to nearby planets and (somehow) forcing them to consume all sentient life so quickly that the Flood overpopulate and cannot survive.
The main flaw in this theory is that it assumes that the Flood cannot spread further from the target planets, i.e. that there is no FTL technology there. If there is, then the Halos have helped the Flood spread – potentially beyond the range of any Halo. This would appear to be counter to their purpose of preventing the Flood from spreading.
The second flaw is that the Flood have not died off in the time it has taken for the Covenant and Humans to develop sentience. They have remained in stasis for over 100,000 (local) years on the first Halo. Perhaps this was something that the Forerunner could not predict. Regardless of how the Halos actually work, this basic fact – that the Flood have not died out in the millennia since the Halos were fired – is a significant flaw in the Forerunner’s strategy to stop the Flood.
Perhaps the fact that the Flood are confined to the Halos is the best that they could achieve, and the Galaxy has been given an opportunity to regenerate itself – much like a forest fire helps the new saplings germinate and grow. 343 Guilty Spark’s comments at the end of Halo 2 would seem to indicate that the Forerunners had run out of options, so maybe they reckoned that the best that they could do is minimise the threat of the Flood as much as possible, with the hope that the Galaxy would come up with new sentient beings that might find a way to truly neutralise the Flood. And if they too failed, then the Halos still remain to do their job, like a galactic reset button.
Except that we broke one….