"This indeed looks like coal! Let me have a feel," said the child who was holding the torch.

Quickly, the children passed the piece of coal to each other. They were very familiar with it since it was commonly used in the village. Although they used a lot of dry branches from the forest when making a bonfire, there would always be a layer of coal under the branches.

"We should not waste more time. Our mothers would be worried if we take too long!" said Mira.

Zeke nodded and took back the piece of coal. With a quick swing, he drew an arrow on the wall, indicating the direction of the exit.

"Let's take this turn. It is our first time here, I think it is better to stay as a group!" said Zeke. He was already acting as a true leader and none of the children wanted to go against him. He was indeed the strongest person in the group and when facing the unknown, it was safer to be with him.

The children went deeper into the tunnel. Quickly, they found several other tunnels linked to that one, but these ones were different. They were smaller, the side-tunnels only had a diameter of about 1.2m which was barely enough for Mira and the short girls to enter but not for the boys.

Despite their age, the boys already looked like young adults; even Zeke was at least 1.8m tall. He could naturally enter the side-tunnels if he bent down and crawled but that would be a very uncomfortable position and as a result, they decided to stay on the larger tunnel.

"D*mn. Why are all the tunnels so small! It looks like it had been made for children!" complained Zeke.

Mira was silently walking behind her cousin. She kept poking the firefly which strangely chose to stick to her. Along the way, they also met a few other fireflies but none of them approached the children. They simply flew around in a random manner and would simply evade the children who would try to catch them.

"Look! There's something in this tunnel!" suddenly exclaimed one of the children at the back. He was holding one of the torches and decided to have a look inside the tunnels. To his surprise, he saw something shiny stuck on the roof of the tunnel.

"What is it?" asked Zeke who quickly stopped moving.

With a quick look, the children found that there was effectively something shiny in the tunnel. It was not very far; about 20m away from the main tunnel. In normal circumstances, they would have never gone inside those small tunnels, but now, they were all curious about what that shiny thing could be.

"I will go!" declared one of the young boys. He was merely 10 years old and was also the shortest one among the boys. Coincidentally, he fitted perfectly inside the tunnel and could walk normally.

He quickly grabbed a torch and ran to the shiny thing. The children were all watching him with curiosity.

"What is it?"

"Did you find anything?"

The children shouted but the boy did not answer. Instead, he drew out his knife at his waist and started poking around the shiny thing. The children did not understand what he was doing but a few seconds later, he ran back, carrying with him a shiny stone.

"What is that?" asked Zeke while snatching the stone from the boy without moderation.

He grabbed the stone and closely examined it. It was his first time seeing something like that; the stone looked just like a piece of rock except for a few shiny grey marks here and there.

"I have never seen anything like that! We should bring this back to our parents. They might know more about that," commented one of the children.

"Let's continue to explore. If we find other rocks like this, we shall take them back to the village," declared Zeke.

...

Five was ecstatic. While he was focusing most of his attention on making the labyrinth, the corner of his eyes could still capture the children's actions. He could see how they were slowly progressing in the tunnel. In fact, he was delighted to see them pick up the piece of coal and the iron ore.

More importantly, Five could see his balance of DP slowly growing up! The number would refresh every second and kept climbing up. It was his first time seeing that and he had to admit that the feeling was just like receiving his first paycheck.

The number was not increasing very fast, but it was steady. DP could be obtained from any living organism in the dungeon that did not originate from the dungeon itself.

As a result, both players, NPCs and even monsters from the open world would generate DP as long as they were in the dungeon. Alternatively, if these were killed by Five's monsters when they were outside the dungeon, he would still obtain some DP.

The stronger the individual, the more DP they would produce per hour. For each level, an enemy would produce 20 DP per hour in the dungeon and if they were killed, they would produce 1000 DP per level. It sounded like a lot but considering the cost of the monsters, there was really not much profit.

More importantly, the DP produced was also dependent on the fatigue level of the individuals and so, the longer they stayed in the dungeon, the less DP they would produce. There was also a cap to the amount of DP an individual could produce per day. This was set up to prevent the dungeon masters from simply imprisoning others inside the dungeon to use as DP farms.

Right now, there were only 23 children in the dungeon but even as children, the weakest one was still level 6 while the strongest one, Zeke, was level 12. Together, they produced about 4000 DP per hour. It sounded like a lot but that was simply because the children were currently not killing any monsters.

Only a few minutes went by since the children entered the dungeon but Five already obtained more than 200 DP. This rate was extremely fast compared to when he was hunting slimes at Kroff's dungeon.

Five was delighted as he saw that the children were already producing so much DP. When the adult barbarians would come, just how much would he obtain?

At the same time, Five finally finished the plan of the Labyrinth. He silently walked through the empty cavern, followed by Lumen and Dreidus. The two monsters were both very calm and instinctively knew what their master was about to do.

When they arrived at the other end of the cavern, Five finally pressed the confirm button on his interface. Suddenly, the amount of DP he had plummeted by 4000 as walls of solid indestructible materials rose from the ground behind him. To save some DP, the walls were relatively thin, but they would still be able to achieve their purpose.

"Rumble rumble!" The ground shook slightly.

Just like that, the labyrinth was now ready. That alone already cost him 12000 DP and he did not even add death traps or summon monsters to wander in the labyrinth yet!

It was an extremely high cost for just a second floor but that was because Five went for a floor that could still be relevant in the future. A labyrinth could still be useful in the future and could stall for time. He was lucky that the harpies came across some enemies and funded him some DP.

Five was now left with a little over 15000 DP, it was less than 30% of his original balance but fortunately, the children were producing some DP.

"Dreidus. I doubt they will reach the second floor today. But let's summon some undead monsters just in case," said Five.

Next to him, Dreidus nodded. "Then, I suggest summoning some skeletons. They are the simplest and most common undead and are easily controlled. I myself can summon some!"

"Good! You can look after them then, but don't show yourself. I don't know your strength, but I doubt you will be able to survive if the barbarians were to come there."

"Of course, master! I will be very careful. I don't need to personally be there to control the undead monsters. As a necromancer, I have a skill that allows me to communicate with undead telepathically, [Dead Mind]."

Five nodded and without waiting, he opened the interface where monsters could be bought. After speaking with Dreidus, he had already filtered the monsters he was looking for. In front of him, only icons of undead type monsters could be seen.

He did not hesitate and promptly unlocked "Skeletons". Another 5000 DP disappeared from his balance.

[System prompt: Congratulations Player Five. You have unlocked the monster: Skeletons. They are now available for purchase!]