The Fourfold Maintenance Litany

A round chamber of damp basalt opens around a sealed stone door veined with pale mineral crystal, its four plaques catching torchlight like wet teeth. A bronze wheel stands in the center on a cracked plinth, and four hanging tablets sway faintly in the stale air, each etched with a short line of verse and a matching symbol. The floor is slick with mineral seepage, and whenever the plaques are touched in the wrong order, a pulse runs through the walls with a low grinding thrum while cold mist exhales from a grate near the floor.