Conundrum
Simultaneously, his two brothers also dozed off, falling into a deep sleep. Osai still held the ethereal wooden box in his hands. The substance that made up their bodies and that object was composed of light and dust, and there was nothing that could come into contact with it.
"What? Hey! That's it? You didn't give us any other information! How long do we have to solve the riddle?" Enatsu gulped, waving his arms at his interlocutors.
*grk*grk* - The echo of the merchant's words was followed by a rock noise coming from the sidewalls of the narrow room. The entire mine began to shake, and the three adventurers struggled to maintain balance.
"Um... Enatsu... I think that's the answer to your question!" Yoichi exclaimed, pointing to the right wall, partly illuminated by Nobu light plus that of the three spirits.