Right. I was just thinking maybe there was atleast some way to trap a single cell. I mean don't get me wrong, what you're saying makes total sense. But its not like they can't sacrifice someone for it, hell ONI does the shadiest things in the Halo universe. Like you said, the Forerunners couldn't devise a cure, but I mean its not impossible to capture one little Flood infector, or even supercell. Granted it wouldn't even have to be a person, even just an animal would do. They could learn from it, the Flood seem to be not so resistant to extreme temperatures. I never understood why the UNSC or ONI doesn't develop some kind of mass fire or extreme freezing weapons. The Covenant figured it out early and started glassing them to subdue them. Idk, just a thought. One thing I never understood is how Forerunners detonated STARS, but yet that didn't stop the Flood. Like wut duh hell. One last thing I just thought of is we never hear anything about Forerunners utilizing or even describing any of their knowledge on black holes, which is weird. A sun going supernova and turning into a black hole sure seems sufficient enough to put down the Flood if you ask me.