Carved above the altar, legible by your own light
The inscription
"HERE THE HOUSE KEEPS WHAT IT TAKES. FIRST BRING THE LIGHT, THEN THE KEY THAT KEPT THE DOOR, LAST THE KEEPSAKE OF HER NAME. IN THAT ORDER AND NO OTHER, THAT THE ONE WHO HOLDS THEM MAY BE COUNTED, AND ANSWERED."
Below, in smaller characters, worn shallow:
"ANSWER THE STONE WHAT IT HOLDS, AND IT WILL EMPTY ITS HANDS."