>>43363751I'm going to guess it was somehow more insidious and incorporeal than your typical alien or chaos incursion. The scant few pieces of lore that reference it to have survived mention a 'labyrinth of dust and electromagnetic forces' or something along those lines. I mean it would have to be something spectacularly pernicious to humanity if was even heavily censured than the known enemies of the Imperium, especially in the region of the Ghoul Stars.
