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.

The two walls on either side of the three tamers were slowly advancing towards the centre of the room, tightening more and more. Looking in the direction of the three tombstones, it was possible to notice that the two outer ones became closer and closer to the walls.

The rocks closest to the side ends were gradually swallowed along with the black mud, which, muttering, was slowly ejected over the walls, out of the room.

"Goddamn! What... what's going on? The room is shrinking!" Enatsu yelled, panicking. He and Shioko approached Yoichi, standing in the middle of the cave.

"Fuck... we will end up crushed in the rocks! We have to answer those guys if we don't want to die in here!" Shioko boomed, evidently frightened. The thought of not being able to solve the quest with a fight put her in great difficulty.

"Judging by the speed with which the walls move, I think we have a maximum of two more minutes left," Yoichi spoke, trying to make an approximate calculation.

"Two minutes? Are we kidding me? What kind of game is this?! Not... we will never succeed!" terror in Enatsu's words clouded the minds of his comrades, and general nervousness took over.

Shioko, not mainly carried for riddles and memory games, clenched her fists in anger. Her level of tolerance for the merchant's useless chatter reached its limit and, to vent her frustration, she grabbed his cloak, jerking it towards her.

"I'm sick of hearing you babbling gibberish!" she shouted, shaking Enatsu like a rag doll. "You're an aspiring wizard, right? So shut up and get us out of here, you smarty-pants! she continued, pushing his partner.

Enatsu fell with his back to the ground, and his gaze pointed towards the ceiling. As he tried to recover from the unexpected hit to the tailbone, the rocky wall slightly touched his head.

The room sides had advanced so much that the already narrow space of the cave had shrunk to just over a meter and a half. "Aaargh!" he yelled, standing up hastily and returning beside Yoichi.

The young tamer remained a few more seconds silent, still looking at the headstones. The walls touched the two outer tombstones, pushing strongly towards the centre.

*track*crack* - the hard rock of the graves of the three miner brothers began to crumble under the incredible force of that magical room, ready to swallow anything inside of it.

Yoichi looked at Kenji, then his companions. They trembled like leaves, and time kept flowing inexorably.

"If we have so little time, it means that the solution is within our reach. Come on, think with me... who can be the culprit among the three?" he asked, trying to attract the attention of his guild companions.

"None of this would have happened if you hadn't been a stupid speedrunner! If you'd known this room was hiding a trap like that, you'd never let us in! Enatsu barked again, out of control as usual.

"What? I won't take any criticism from a useless brat like you! What have you done so far, huh? A goddamn thing! If it wasn't for Yoichi or me, you'd have died hours ago, mauled and eaten by one of the demons we killed and..."

While Shioko rebuked Enatsu, Yoichi stepped forward. Without adding anything, he quickly approached his merchant friend and hit him with a loud slap on the face.

The blow was strong enough to silence both litigants, instantly restoring order. "Are you going to help me or not?! In about a minute, our bones will be crumbled under the walls!" the young tamer yelled violently, scolding both of them.

*crash* - As the outer tombstones crumbled and the walls continued to approach the central one, Shioko and Enatsu returned with their feet to the ground, breathing hard due to the cave's lack of oxygen.

Anoxia, the tight spaces and the lack of light were all elements that made any logical reasoning difficult. If they had more time and would have been free to move around, the three travellers would have found a solution in a short time. But would they be able to coordinate their anxious minds in that conditions too?

Who was the cheating brother? Were the clues they had enough to draw conclusions? Why did the spirit named Osai hold that wooden chest in his hands?

The questions that gripped young Yochi's mind were many, but the survival instinct forced his mind to think neatly and schematically.

"The only thing we know about them is that they are brothers... and that Ysai is the oldest. Right?" Enastu asked, who finally wanted to get involved.

"Correct. We also know that when the demons began to conquer this place, they ran away, but before they reached the exit, one of them forced them to stop in this room", Yoichi added.

"What else... what else may have escaped our attention? It must be an important detail... something we listened to superficially... but what?"

As Yochi and Enatsu tried to come up with a solution, Shioko put a foot on the wall. Forcefully, she tried in vain to stop it, trying to estimate its movement strength.

The two outer tombstones disappeared under the rock, voraciously devoured by the room itself. No longer having the space to stay next to each other, the three explorers were forced to line up, occupying as little space as possible.