Kai read the folder that night.
Twenty years of zone 5 substrate monitoring data, accumulated in the standard Guild format: date, depth reading, classification result, anomaly notation. For the first three years, every reading returned standard geological results—bedrock composition, sediment layer densities, the kind of substrate data that zone management teams filed and never read again.
Then year four, entry 312: anomaly. Unknown construction signature at substrate depth 205 metres, zone 5 interior eastern section. Classification equipment returned no valid result. Notation: pre-Guild construction signature possible. Filed as unknown pending further investigation.
Further investigation had never arrived. The anomaly appeared in entry 312 and in every reading after that, the notation cycling through "unknown substrate signature" with the regularity of something the monitoring equipment had learned to flag without anyone learning to understand.
