Not far from the entrance of the cave, half a shallow shoe print was left alone.

The heel part of the shoe print remains, and the front half has been erased by the smudge monster's movement on the ground.

Judging by the direction, someone walked here from the direction of a nearby river for some time, leaving it behind on the way to the entrance of the cave.

Judging by the size of the shoe print, it is likely that the other party is a man. However, it is impossible to judge the weight, because the moisture content of the soil at that time is not known.

The traces left by the mud monsters on the ground are also quite suspicious, these mud monsters swarm out of the hole, and after leaving the cave entrance, they almost always walk in a straight line, and there is no trace of them staying, as if there is something terrible in the cave.

This discovery made the two of them instantly lift their hearts, and it seems that this matter is indeed not simple.

There was a slight wind blowing from the entrance of the cave, and they prepared their lamps and slowly walked into the cave.

It's just that all the clues on the ground and around the ground were erased when the sludge monster came out, especially the king of the sludge monster, who could see that it was squeezed out of this not wide passage.

The dirt on the walls was still damp, and Charles took some samples back from small glass bottles.

The collapsed passage was more than twenty meters long, and the two soon came to the complete passage.

The main road can accommodate two horse-drawn carriages side by side, and the height is considerable.

They found a lamp bowl on the wall, the stone bowl was already full of dirt, and through mental exploration, there were many carbon marks left by oil lamps on the top of the passage above.

"It's an oil lamp?!" Charles was surprised.

Because the history of lighting magic circles is extremely long, most of the artificially built dungeons are lit with magic lamps, unless the local magic power is thin or the party building the dungeon is too poor.

There are two other possibilities, one is that the dungeons were built before the magic lamps were invented, and the other is that the oil lamps had some special function or religious purpose.

The two studied it for a moment and had no clue, then headed deeper.

Soon after, two symmetrical doorways appeared on both sides of the passage, and after some exploration, there were rooms of about ten square meters in size, and there was nothing in them except for the traces of the life of the mud monster.

The discovery that followed made Charles think that the party of the dungeon had obsessive-compulsive disorder, because the rooms that appeared on both sides of the passage were all symmetrical, not only the same size, but also the position of some stones that appeared to be stone tables and chairs.

Unfortunately, the environment here is quite humid, and there are mud monsters living there, so nothing of value has been preserved along the way, only some crude clay bowls and pots and other fragments of utensils have been found, and there are the bones of the occasional animal that came in from outside.

"It's weird. Artoria said, "There are so few elements of magic here. ”

Charles nodded, the deeper he went, the less magical elements there were around, and he said, "Indeed, this is very abnormal, there may be something that is absorbing the surrounding magical elements." ”

"What do you think this place is for?"

Artoria thought for a moment and said: "This main road leads straight underground, there are no turns, it cannot be fortified, it should not be a military building. ”

"The rooms on both sides are very much like storerooms, and there is no place for the kitchen or anything like that. ”

The two continued to walk inside, and after walking for a while, the rooms on either side changed, and suites began to appear that looked like two-bedroom and three-bedroom layouts.

At this point, there are fewer and fewer magical elements around, and ordinary magicians can't cast magic.

Charles Ke said, "Could this be the Forbidden Demon Realm?"

Artoria shook her head, she didn't know everything, and there was no alarm from the main body at the moment.

They walked slowly for nearly an hour, and a stone door appeared in front of them with the right half of the door half-down.

"Shh......hhh ”

Artoria frowned and said, "Get ready to go in again." ”

Charles nodded, he felt a slight wind blowing out of it, but he didn't know what was going on with the wind while wearing a gas mask.

Artoria walked ahead with an Ex curry stick and was the first to enter the stone gate. Charles held the black chicken leg staff, and all kinds of magic shields were brushed layer after layer.

Inside was a huge cavity, thirty or fifty meters in diameter, and there were several huge cavities in the ceiling ten or so meters high, from which it looked like fresh air was flowing in. In the middle lies an altar-like high platform, on which the magic element is the strongest. The ground was muddy, full of traces of the activities of the sludge monsters.

They quickly walked away and found that there was a pile of ashes deep inside the hollow, which looked new.

Artoria flicked her sword a few times, and pulled out a little unburned plant at the bottom.

Charles carefully identified it, and said in a cold voice: "I know a herbal recipe that will emit an unbearable stench when burned to make people and demonic beasts unbearable, and the effect is the same as the 'stinky beast' potion, and these herbs are one of the recipes." ”

Artoria said, "You mean someone is burning these herbs to drive the sludge monsters out here?"

Charles nodded and said, "I speculate that this is the base camp of the Sludge Monster, and one of the Sludge Monsters who lives here has evolved into the King of the Sludge Monsters because of the strong magic element. ”

"Someone came here not long ago, and I don't know what the purpose is, and drove all the mud monsters out. ”

Artoria was noncommittal, holding up her searchlight to scrutinize the surrounding walls for any useful clues.

Charles used his mental powers to probe the ground, occasionally collecting some samples of dirt to analyze when he returned.

However, there was not a trace of useful clues, as if the pile of ashes had come out of thin air.

However, if the person who comes in is flying, this is normal.

Finally the two of them came to the stone platform, which is the most special place in this dungeon.

Artoria's body suddenly moved, "There's a lot of energy underneath. ”

Charles used his spiritual power to study the stone platform, which was less than ten meters in diameter and more than one meter high, and said: "It is divided into three layers, the middle layer is a huge but ancient magic gathering array, and the gathered magic power is transmitted to the ground, and the top layer should be the protective layer. ”

"The most important thing is that there is a passage in the center that leads to the underground, which can be seen when you lift the stone slab. ”

Artoria looked at him and said, "Do you want to go down?"

Charles nodded, he jumped onto the stone platform, removed the floating dirt on the top, and pried open the circular stone slab in the middle, and a hole with a diameter of more than a meter appeared in front of them.

Then he crouched down next to the entrance to the cave, took out a ball-shaped magic lamp, lit it, and threw it in.

There was supposed to be a slope inside the cave, and the magic lamp fell vertically for a few meters before gurgling down, without the sound of falling down the stairs step by step.

Then it was a "terrifying spider" with a diameter of half a meter, and the footsteps of "click" changed from large to small, without any sound of battle.

"Looks like it's safe down there. Charles breathed a sigh of relief, "What do you think will be next?"

Dumb Hair shook at a faster speed, and the carrier said, "There may be a terrible existence inside, so we must destroy it, otherwise the damage will be worse than the plague." ”

Charles stood up, swapped his gas mask for an oxygen tank and mask, and jumped off.