The Door That Remembers the Sky

You enter a circular chamber of black basalt, cool enough that every breath briefly clouds. A thumb-sized blue flame burns in a wall niche, casting a wavering reflection across the polished floor. Three silver tumblers rise from a waist-high pedestal, each engraved with a mountain, crescent, and star. Opposite them, an apparently blank section of wall bears a faint rectangular outline. Dust gathers everywhere except along that outline, and a shallow basin of water trembles with a soft ringing whenever the pedestal is touched.