The map used by crews at the Lantern Fault still carries a collapse mark beyond the fourth station. The mark appears in the copy register before the current lamp checks began. Those checks record a warm draft that changes direction, but they do not show whether it comes from an open passage or a gap in the old working.
Rava Thenn reviewed the map copy, the lamp log and the sealed bag of stone chips recovered near the marked stations. The log gives each reading a position; the map does not say whether the collapse was surveyed directly or copied from an earlier plan. The archive has not located a field note that resolves that difference.
Geology reader Gevra Sol said the crew had not crossed the marked limit. A remote lamp is to be lowered from the last confirmed station, with a second reader recording its direction and the time it is held. No one will enter the suspected passage to make the measurement.
The evidence supports a narrow conclusion: the draft is real, and the old map is incomplete about how the collapse mark was made. It does not establish that a new route is open. The east crew will remain outside the boundary while the map and the next reading are compared.
