Ash That Fell Upward

The crew reached a slag basin during a windless period and found ash rising from the ground in narrow columns. Each column followed a different temperature gradient. When the Ashwalker stepped between two columns, both bent toward their body and held there.

No fire was found beneath the basin. The ash contained no ordinary fuel residue and cooled only after the team crossed back into the service tunnel.

The public record calls the event a localized thermal inversion. The Ashwalker's statement is shorter: something below was still trying to exhale.