Across the damp underground check landing beneath East Culvert Junction #4 at forty-five minutes past midnight, the work of the hidden fan behind the mortared wall began not with grand proclamations, but with Foreman Eren Tal, Retired Lock Operator Renn Vos. Corvin Hest inspecting Imran’s white indicator strip—now stained jet-black by rotten-egg clay vapor—and a newly bricked-up partition wall whose grey lime mortar was still soft enough to take a thumbnail print alongside Pella Rook and thirteen-year-old Tavi. Following Imran’s overnight airflow plan, Foreman Eren Tal’s volunteers and Corvin Hest trace the midnight heat draft down the eastern service passage and discover a hidden backup fan turning behind a freshly mortared ‘sealed’ wall.
The technical core of the hidden fan behind the mortared wall needed Renn Vos pressing his brass-tipped ash sounding rod against the fresh brick partition to count the clear four-hundred-revolutions-per-minute thrumming of a belt-driven iron blower wheel turning directly behind the ‘abandoned’ wall. Throughout this phase of the systematic cellar-to-cellar mapping of the lantern beetle colony, the crew held fast to reading living shifted weight as a heat map of the hidden trunk. Every brass fitting, every stitched seam. Every thirty-minute lunch crossing had to answer to physical measurement rather than guild politics.
