The ’thopter dodged and leveled out, circling back. The twister’s middle looked treacherously empty: a core of utter nothingness with a great black wall melting down from above, and a bottleneck of tortured dirt rising up. But then the wall’s funnel moved down very suddenly, in four thick, churning, separate runnels of octopus ink, and it seized the little dust whirl and ate it, and the world was filled with a terrible sound.