The gas jets lessened and ceased. The corridor below them had emptied of its air quickly, suggesting to Voldo that it was sealed. He mentally calculated its volume based on the amount of gas he had seen vent. A thought brought up the incomplete map they had of their immediate surroundings on to his visor display. The surface corridors had been as thoroughly scanned as circumstance allowed and were well-defined, but further in, and especially closer to a nearby reactor, the map faded into probabilities, and then blankness. He compared the conclusion to his calculations with the map. It appeared they matched, and so they should. He grunted with satisfaction.

Death of Integrity pg. 88