The Fourfold Engine

You find a circular chamber of black basalt, warm beneath your boots despite the dungeon's chill. Four alcoves surround a waist-high console, each holding a different mechanism: a heavy stone plunger, a whining copper fan, a blue glass basin, and a red iron wheel. In the center, a brass dial rests beneath a dark crystal needle. Dust trembles whenever the apparatus exhales, and a sealed basalt door glimmers with four dull points of colored light. Somewhere behind the walls, something small and furious beats like a trapped heart.