It--

[ He doesn't want to say. It's a terrible thing. A weapon that should never see the light of day nor occupy anyone else's mind. ]

It was created by...a certain people, [ he says cagily. ] Those caught in it would suddenly be drained of their vitality and drop dead where they stood. It spread across the land like an infection and nothing was able to halt it. Anyone who didn't succumb to it died in the ensuing fight for resources.