Elsewhere, Shu is inspecting these turbines, which were about to be worn out, and estimated that these turbines are still viable for operation. Yukari and Ken are walking in another part of the turbine's room, aiming their flashlights in all directions to check their surroundings. Shortly after, their single earphone turned on, followed by Makoto's voice.

"I found something; come to the control room above you all."

Shu, Ken, and Yukari looked above them toward the control room; they then walked up the circular stairs toward the control room.

In the control room, the four of them finally regrouped. Makoto showed them the old log records he found; everyone read them with curious expressions. Makoto showed them the keyway on the control dashboard.

“I've read the manual book; all we have to do is turn this keyway and start all the turbines in the desired setting and sequence with pauses. The sequence is in place, and it remains only to find the key to turning on the control of these turbines.”

Shu’s expression turned serious.

“Let me try something.”

Shu tried turning the keyway using his unlocking tool, which had long and small metal shapes of various shapes and sizes connected to his smartphone. Seeing that, the others looked astonished. Yukari said

"Uncle can even break into the transponder keyway like this?"

Shu looked awkward

"Yes, I have much experience as an investigator, hahaha".

Shu laughed awkwardly. Shu managed to turn the control keyway, and a few moments later, the starting engine sound was heard.

"And turned on, now what?"

Makoto walked to the front of the control dashboard

"I will operate it according to the instructions given in the log book."

Shu invited Makoto, Yukari, and Ken to watch curiously. Makoto began to operate the turbines by the controller according to the instructions in the log book. In the water tunnel below the turbine's room, rushing water flows from the river and rotates the turbine above it.

Back to the control room, the view outside the window pane in front of them showed that these turbines below started to turn on in the order Makoto had adjusted. After each turbine started rotating, there was no other response whatsoever. That made all of them look confused, they then tried to look at the scenery outside the window on the other side of the control room, but still, nothing else happened. Makoto said

“Weird, the sequence should be correct….”

Not long after, there was a quake followed by a loud rumbling sound that lasted for a while and finally stopped.

On the outside, one of the waterfalls in the middle of this dam building started to stop flowing after a thick steel barrier raised from the bottom of the water and closed one of the water tunnels, which made this waterfall has now completely stopped flowing and showed a concrete double door behind this waterfall. Not long after, the concrete double door slides open to the right and left. A concrete bridge that is as wide as a two-lane highway emerges over the slope of this dam which leads right up to the secret double doors, with rectangular holes for each still-flowing waterfalls. Back to Makoto and the others, they appeared a little unsuspecting of what had just happened. Makoto said

“What happened just now might be some kind of heavy mechanism of this dam.”

They looked around them curiously but found nothing. Ken said

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"There is no opened secret door or anything changed here, Grandpa."

Makoto was silent in thought for a moment; he appeared to realise something.

“A mechanism that is heavy enough to shake this large dam building definitely makes something to change in here; let's try to check outside.”

The others nodded in agreement, and they then walked out of here.

Outside, from one of the locations of the base point of the suspension bridge that fell in front of the dam, they can see a secret door behind the waterfall with a concrete bridge attached to the dam leading to the secret door. Seeing the unusual location of the secret door and the emergence of concrete bridges on the slope of the dam buildings, their expressions turned surprised and astonished. Ken said

“Grandpa was right; there are doors and bridges that emerged from the dam building."

They looked amazed. Before long, Shu appears to realise something; his expression then turns astonished.

"How could Fujiyama find a place like this? What's with this dam anyway.”

Makoto’s expression turned serious.

“Whatever it is, it might have something to do with a centipede Yokai appearing in this place.”

Everyone's attention turned to the ruins of the suspension bridge at the river below, which fell over the fainted centipede Yokai who still didn't move from his place. Makoto said

“I don't know what will appear after this; before we head to that open door, we better call Asanuma and Shinra to be alert.”

Yukari and Ken nodded; they then concentrated and Summoned Asanuma and Shinra back. Black smoke began to billow from the glove puppet Asanuma and the stuffed doll Shinra then enveloped them, and from behind it, Shinra emerged the size of a tiger in general. At the same time, Asanuma was the size of a wolf in general. Asanuma looked at Ken and Yukari with a slightly astonished expression and smiled.

“Looks like you guys are getting good at this, huh? What else now?"

Ken smiled

“We're going to the secret door that opened at that dam.”

Ken said while pointing towards the secret door behind the waterfall; Asanuma and Shinra then looked there. Ken resumed talking

“We want you guys to come to watch over us.”

Asanuma nodded

“No problem, kid, I understand.”

Shinra and Yukari looked at them with slightly astonished expressions. They all walked across the bridge together and headed for the secret door.

While walking on the bridge, they looked around them with astonished expressions. Shu appeared to have realised something.

“Whoever made a strong and wide bridge mechanism leading to the door, I don't think it's just for people to pass through.”

Makoto nodded

“Right, from the width of this bridge, it is probably meant to allow even trailer trucks to pass over it. Upon our arrival, I had suspicions as we passed the wide concrete road leading to the dam before this.”

Yukari’s expression turned astonished.

“Why do they need a trailer truck to a place like this?”

Makoto replied

“I don't know; maybe that's what Fujiyama was also trying to investigate.”

Hearing that, Yukari’s expression turned serious.

Arrived at the tall and wide secret door, they then walked in. The room behind the door was a large freight elevator with a shape resembling an airplane hangar with lights illuminating from its high ceilings and doors shaped similar to the entrance on each other side of the elevator. They checked around; Ken then found a control panel for this freight elevator.

“I found a control panel here.”

The others then walked over to Ken. Yukari’s expression turned curious

“Where is this elevator will take us….”

Shu’s expression turned serious.

“There is only one way to find out.”

Shu pressed the button on this control panel, and not long after, the tall automatic sliding door behind them closed and made them slightly surprised. Shortly after that, they could feel this freight elevator moving down.

Sometime later, the elevator stopped, and the elevator door opened on four sides. As soon as the elevator doors opened, the lights on the ceiling in the room in front of them outside the elevator lit up, and they then walked out of the elevator. They arrived at a high hangar room with thick steel frames on the ceiling and walls. The height of this hangar is equivalent to two levels of a building and it has piles of containers and countless large item steel chests piled up, some of which are open and empty. Ken looked around with an astonished expression.

“What with this pile of chests… this place is getting increasingly suspicious.”

Yukari looked curious

“Even so, this place seems to have been abandoned for quite a while.”

Makoto’s expression turned serious

“Let's check these chests.”

They checked the chests around them which were closed. Sometime later, they had opened enough closed chests, but none were filled with something. Finally, Shu found a few bullets for an assault rifle.

"Look what I found, bullets probably for an assault rifle.”

Shu said while showing the bullets to the others and making them surprised. Shu looked at Makoto with a serious expression.

“Do you think the same as me about these chests, Makoto?”

Makoto’s expression turned doubtful.

“I don't know, but I think these chests are some kind of container for storing weapons.”

Shu nodded

“But what kind of person or people had this many weapon chests anyway.”

Their expression turned serious.