Three thousand years after the surface became uninhabitable, humanity's descendants survive in the Hollows — a vast underground megastructure of abandoned strata, dead sun-strips, and bioluminescent fungal forests. The technology that built this world is magnificent and failing. The Bloom — a nanotechnology swarm gone wrong — consumes everything it touches, advancing slowly, inevitably. In the silence of cathedral-scale ruins, the last AI watches the clock run down.
