New Vance City

Gratewash Sinkline was an overflow maintenance corridor turned unofficial shortcut between under-river transit lines. Its original function collapsed after the flood systems failed during the early days of the Collapse. When the river surged into the lower tunnels, this stretch became one of the first partially submerged zones. Now it functions as a natural trap—waterlogged, pitch dark, and echoing with movement. Shamblers gather here in dense clusters, clinging to the walls or floating face-down in stagnant eddies. Any attempt to clear the tunnel is rendered impossible by sudden rises in water pressure or silent bio-thrashing from submerged infected. Motion sensors last only hours before corrosion ends them. No patrols are assigned to this sector.

The entire corridor dips below the waterline at a sharp angle, forming a waist-deep trench that stretches for hundreds of meters. The railbed is warped and rust-flaked, with twisted metal protruding from beneath the surface like the ribs of a drowned beast. Overhead lights hang from half-collapsed cable harnesses, flickering just enough to reveal shapes under the water—some humanoid, some not. Mold clings in strips to the curved tunnel walls, pulsing faintly with bioluminescence. Occasionally, a pair of pale arms drift up and vanish again beneath the green film. A single emergency exit door stands open midway through the corridor, but it leads only to blackness and wet echo.