The Three Lights of the Lanternwright

You enter a circular chamber of black stone, where cold blue light leaks through veins of crystal in the walls. At the center stands a waist-high bronze apparatus with a shallow basin, a faceted crystal lens, and a keyhole shaped like a three-pronged flame. Dust lies thick everywhere except around these controls. A sealed jug rests nearby, and thin lines of silver metal run from each control toward a sealed door. Somewhere beneath the floor, water trickles. The apparatus gives a faint pulse of blue light whenever someone touches it, as if waiting to be awakened.