Entry hall 180 was a stone-built safe hall unlike any other in the infinite halls of the House.
Known in the ancient cartographic rolls as the Colonnade of the Singing Pillars, the hall was four hundred paces long and eighty paces wide. He was flanked by forty huge giant pillars of semi-clear Carrara-like white spar-stone. Each column was six arm-lengths in width and forty arm-lengths high, carved with hollow internal sound chambers that reached from the foundation flags to the high vaulted ceiling.
These were not load-bearing piers; they were giant organ pipes of stone.
When the air of the hall moved through the subtle air-flow slits carved along their fluting, the columns did not remain silent. They rang with a pure, nonstop drone—a deep, soothing hum of one hundred and fourteen cycles per second, the deepest pitch of the Drowned Dao.
Into this sacred forest of shaking stone marched the final heavy infantry reserve of the Obsidian Scroll hall: six hundred shock-fighters clad in full suits of dark void-iron plate, led by Commander Shen Tu. These were veterans of fifty void-sieges, their minds hardened against mental illusions, their heavy tower shields linked by magnetic copper locks to form an iron-hard, moving iron castle.
