The defense outer edge of Sector 7 had stood for over eighty years. A grim, thirty-foot castle wall of dark river slate, heavy with linked granite keystones, iron tie-rods. Then it backed by heavy timber support galleries. It had weathered seasonal monster migrations, minor rift surges, and the bitter winter blizzards of the northern frontier without yielding an inch of ground.
At seven in the morning, that venerable bulwark crumbled into thirty thousand tons of flying gravel, crushed stonework, and crushed bone.
The collapse began not with an artillery shell, but with a sound like a continent snapping in two. Beneath Wall Section 8, the underground tunnel diggers had done their horrific work with terrifying, bio-chemical smooth speed. For six hours during the midnight lull, hundreds of Burrowing Gorgon Sappers had pumped millions of gallons of skin-burning, acidic stomach bile directly into the limestone foundation beds beneath the wall footing. The acidic secretions had dissolved the mortar into liquid slurry. That turned the underground bedrock into a honeycombed, load-bearing void that could no longer support the weight of the stonework above.
Then came the battering rams of the Beast Tide: three Disaster-Substrain Siege-Behemoths, known to frontier veterans as Chitinous Crag-Crushers.
