The Bronze Lung of Ashfall Cavern

A circular cavern chamber hums with damp cold, its walls webbed in bronze pipes that bead with condensation and occasionally throb like a living pulse. In the center sits a waist-high machine of gears, vents, and a soot-black wheel, while two floor plates and a dripping basin frame it like ritual pieces on a board. Every wrong touch answers with a hiss of steam and a shudder through the stone, but each correct motion sends a brighter click through the apparatus and a thin ribbon of clear water into the drain channel.