Infinite Realm

A low-intensity orange light spread into a dark room, occupying the entire area and illuminating the dark cold room. However, as the light kept spreading, it soon encountered an obstacle in the form of a wall preventing it from going any further.

"Another dead end." A sigh rang out in the light room.

"I'm sorry." Xue Yan apologised with a low voice.

"It's not your fault. It's just how things are." Sato comforted her.

The duo had already spent more than 45 minutes within the cave, exploring it in hopes of finding an exit. As they did so, they discovered that the cave was much bigger than they had thought, almost becoming a whole different ecosystem from the outside world. Along the way, they had come across different forks that lead to different directions. In order to avoid wasting any more time, Xue Yan suggested that she uses [Mana Sensing][1] and try to pick out the right path. Sadly though, while they still managed to enter a few passages that seemed to be the right one, they would encounter more forks that led elsewhere. Inevitably, some of the decisions the duo made regarding this was a misstep and they would bump into a dead end. Currently, this was the 5th dead end they had found but the 3rd consecutive one.

'For there to be so many different corridors, this shows that there must have been artificial construction going on in here. What the hell is this place?' 

Sato began to contemplate on the purpose and basis of this mountain. He had originally thought that it was made by the Caventry to serve as a trial ground but from the recent findings here, it seemed like either the Caventry or another civilization had once dwelt here. This made the mountain seem to be more than just a trial ground. While there wasn't enough evidence to prove this, the fact that there were man made tunnels excavated here, showed that a certain amount of manpower was once mobilized in here or might even still be here.

'If it's the first conclusion then there's no problem. But if it's the second, there's a chance that a monster horde might be hidden deep within.' Sato frowned at that realisation.

"Xue Yan, have you sensed any living creature yet?" 

Xue Yan closed her eyes and focused her attention on her skill, trying to spot any mana outburst/signal or displacement of mana particles within the skill's radius. This took her 5 seconds after which she opened her eyes and shook her head.

"No. I haven't sensed anything since we started heading in or even now."

"Okay." Sato replied.

Despite Xue Yan's feedback, Sato didn't drop his idea of the possibility of a monster horde residing in here. It was quite possible that the creatures were either hidden deep within, at the innermost section, or that the creatures' population was lower than he thought, making it so that they had yet to encounter any one of them.

"Any problem?" Xue Yan noticed that Sato had taken on a serious contemplative expression.

"I have a strange feeling that something's wrong. There's something hidden in the depths of this cave system. If we aren't careful, we could lose our lives and fail the trial." Sato informed her of his suspicions.

"I feel the same way too. These tunnels look man-made but why would someone do such a thing just for a trial ground? It doesn't add up. But it's also possible that we could be over-thinking things." Xue Yan commented.

As he noticed that Xue Yan was similarly skeptical as he was, Sato decided to take his assumption to be the truth. It was better to be safe than sorry.

"We'll move more carefully while you try as much as possible to activate [Mana Sensing]; at least every 20 metres or so. I will reduce the intensity and range of the light to prevent us getting spotted while you be on guard for any surprise attack or ambush. Let's go." Sato gave out his instructions before heading back the way they came from. This was a dead end so there was no meaning to them standing at a spot and staring at the wall. Their trials were timed so every second mattered.

Xue Yan nodded in response as she walked after him.

10 minutes later, the duo were in a large open area within the cave system. At this point, it was more suitable to call it a cavern rather than a cave system. This was because there were a bunch of protruding rocks and boulders scattered all over. Stalagmites, stalactites and other speleothems were spread all over the place turning it into a Speleology[2] wonder site.

Xue Yan had led them here saying that she had sensed foreign mana in the environment. The foreign mana didn't refer to the mana produced from the presence of another creature or being, but mana from outside. 

It should be recalled that Sato had felt that the cave system was like a whole different ecosystem of its own and this wasn't limited to the plants or soil but also the mana. From Xue Yan, Sato had come to realise that the prevailing mana in the cavern was Earth-type mana due to the structure and nature of their location. But now, Xue Yan claimed to have discovered signs of water-type mana. The only way for this to be possible was for there to be a water-type mana monster that resided at the location or at the very least, frequent the area, or that there was a large amount of water in that area. 

If it were a monster, then going there would be pointless but not completely. More or less, they would finally be able to identify the monsters that dwell here and also, chances were that there would still be a water body present since such monsters tend to stay close to a favorable location. If it were a pool of water, a stream or river, the story would be totally different. 

For there to be a water body in this cavern, there had to be a source. Whether it flowed from underground or was a stream or river that flowed in from outside, Sato wanted to find out. To a certain extent, this was their only means of escaping this dark zone. 

Xue Yan's discovery turned out to be true as standing on a elevated rock surface, the two spotted a lake in the distance. They couldn't grasp the size of the lake due to the distance between them, neither could they see a stream or river that flowed in from the open. Nonetheless, they didn't conclude yet that there wasn't any, since the likelihood of there being an underground water channel was still 50-50.

"Let's go."

As the two headed into the open area, they noticed that the pressure on them -which never departed since they were still on the mountain- was steadily increasing. Previously, as they were exploring the cavern, the pressure was constantly undulating; increasing and decreasing at certain turns they took. Now however, the pressure was straight up increasing. This meant that they were actually going up the mountain. But the weird fact was that the land they walked on looked to be a flat one. In fact, it wasn't. They had just descended from an entrance located up on a cliff-like wall so technically, they were descending rather than ascending. In other words, this didn't add up; there was no reasoning or explanation as to why the pressure was increasing.

"Be on guard. This feels weird." Sato said to Xue Yan as he unsheathed his sword and went into a high alertness and awareness state.

"Alright." Xue Yan clasped her hands nervously on her staff as she raised her senses to the highest, trying to spot any changes in the mana fluctuation in the area.

*Boom*

"What was that?" Xue Yan asked with an anxious tone.