The shift from fifteen hundred pounds of crushing oceanic pressure to the dry stillness of the vault was like passing from a battlefield into an empty library.
Giles Croft stepped through the backup airlock door, his heavy rubber diving boots leaving wet, glistening tread marks on the grey iron-hard metal floor plates.
He pulled off his brass diving helmet with a sharp twist. He set it carefully on an extruded bronze check shelf beside the door post.
He didn’t gasp.
He took a slow, measured breath through his nose, analyzing the air with the cold, critical calm distance of a town sanitary checker.
“Cold air seventy-eight percent, oxygen twenty-one percent,” Giles murmured. He tapped the glass dial of his portable air-assay bulb.
“Carbon dioxide point zero four percent. Humidity twelve percent. A bit stale. It smells of spark ozone, dry copper, and desiccated graphite grease.
Good HVAC design. Someone left the intake angled slats locked on closed recirculate.”
