The sound blast wave generated by the backfire in the Hall of Bells did not vanish into the stone. It sank into the bones of the world.
Through the deep red stone foundation slabs of Entry hall 150, the packed striking force of fourteen thousand foot-tons traveled eastward as an underground ground-wave. Moving through the dense metamorphic granite at fourteen deep-water lengths per second, the wave hummed at a deep-rumbling hum of fourteen point eight cycles. A pitch far below the hearing range of the human ear, but felt through the soles of bare feet as a deep, nauseating thrum that made the marrow of the shinbones vibrate.
In Entry hall 170, an intermediate transit pillared hall two hundred paces wide, the reserve sonic company of the Obsidian Scroll hall was hastily preparing to deploy.
Eighteen huge Jade-Core Drums, brought down from the cargo decks of the Celestial Sovereign, sat in three parallel ranks upon the flags. These were ancient instruments, their shells carved from solid blocks of white Hetian jade, their heads bound with gold-plated copper hoops and tuned with silver tension-screws. Around each drum stood four master diviners in lead-lined gray robes, holding heavy mallets of carved star-fallen bone, waiting for the signal to launch a backup sonic barrage through the eastern archways.
