The roar of Siphon Weir 04 was a hollow, throaty bellow that shook through the flat stone slabs long before the water became visible.
Entry hall 003 was designed as a settled mud-settling basin, a huge circular atrium spanning four hundred paces, ringed by thirty-six fluted columns of grey-veined marble. At its center lay the great circular weir—a raised rim of curved red stone fifty paces across, over which the excess floodwaters of the upper terraces spilled into a central vortex that dropped forty deep-water lengths into the deep drainage channels of the keel.
Normally, the water in the basin was calm, rarely rising above the ankles of the statues that guarded the periphery. But the sudden impact of two huge void-arks upon the outer castle walls had cut the main aqueducts in the ceiling, dumping forty thousand gallons of high-pressure water down the western walls every minute.
The basin had become a surging lake of cold, churning salt water.
Across the slippery red stone rim of the weir, a panicked throng of refugees from the third backup hold was attempting to cross. They had been told that safety lay on the southern terrace, but in the dense, freezing fog that filled the atrium, they couldn’t see the wide arched bridge fifty yards to the east. Instead, they had climbed onto the narrow, slick crest of the weir itself, trying to balance upon a ledge barely three feet wide with five feet of rushing water on one side and the…
