... Hmm, isn't this the place we passed before?"
"... Seems so. Are we going in circles?"
Apparently, Hajime's party were going in circles in an annulus ring cave. They had thought the Great Dungeon was ahead of them so they advanced, but Hajime was doubtful that he had mistaken a road here, as if it was a normal bottom sea cave. Resultantly, the party now didn't advance according to the laid road, and carefully searched the surrounding for any clues.
As a result,
"Ah, Hajime-kun. There's one there too!"
"With this, it is the fifth place..."
The party discovered several place inside the cave that were carved with fifty centimeters long crest of Meljeene. The carved crest of Meljeene was of pentagram with lines connected to each five points and the center was carved with crescent moon-like design. It was similar to the five places in this annulus ring cave.
For a thorough examination, Hajime's party approached the crest they first discovered. Because they were exposed to the swift current, Hajime took care in controlling the submarine.
"Well, there are five places with pentagram, so if the remaining light inside the pendant is used..."
Muttering, Hajime took out the pendant he wore on his neck and held it before the front crystal. Then, the pendant reacted and light was released straight from the lantern. Following that, the light touched the crest and the crest shone.
"It will be disastrous for people who come here using magic... if they didn't notice this immediately, their magic power would be depleted."
Just as Kaori said, this RPG-like method would be too cruel for people who somehow survived only by maintaining their magic. It might be because the objective was to make them reach their limit in a different sense than 【Guryuu-en Great Volcano】.
Afterwards, three more crest in their own location was poured with light from the lantern, and the party arrived before the last crest. The light collected inside the lantern decreased when it was released to light up the crest, and the remaining light had enough for only one more usage.
Hajime held up the pendant and poured the last crest with the light, finally, a way to advance from this annulus ring cave opened. With a rumbling sound, the wall of the cave split in two.
Not much happened as the party advanced into the interior, but the water was descending right to below. Then, the submarine was wrapped with floating feeling as it was falling down.
"Ohh?"
"Nh."
"Hyah!?"
"Nuoh."
"Hauu!"
Respectively the five of them raised different scream. Hajime was enduring the floating feeling between his groin. Then, the submarine hit the hard ground with a roaring sound. The severe impact was transmitted into the interior, and Kaori whose body wasn't that strong raised a groan.
"Kh... Kaori, are you okay?"
"Uhh, I-I'm okay. More importantly, here is?"
While frowning, Kaori looked at the outside through the front crystal, and unlike a while ago, the outside was not sea water but a cavity. Because there was no sign of demonic beast, Hajime's party went outside.
Outside the submarine was a huge hemispherical space. When they looked above, there was a large hole, but they didn't know what kind of principle caused the water's surface to sway to and fro. Without any drop of water, it was swaying to and fro, and it was the place where Hajime's party fallen to.