When he took a seat in the submarine, Chen Nuo chose the second row.

A diver was responsible for controlling and steering, while Chen Nuo deliberately avoided looking at the instrument panel's readings and bearings. Instead, he settled down and immediately fixed his gaze outside the window.

Once the two shuttle-shaped submarines, encased like glass cocoons, were placed on the water's surface, the crane hooks on the ship disengaged. The submarines' propellers began to turn, and they slowly maneuvered around, lowering their bows and plunging one after the other into the water.

After being engulfed in the waves and the tumbling foam, everything swiftly became shrouded in darkness.

The journey underwater was incredibly smooth, with hardly any vibration felt.

Ishii Hisako sat next to Chen Nuo, appearing quite calm, though her gaze was constantly on the sea outside the glass window.

Chen Nuo glanced back and saw, in the rear cargo hold, the octopus in the glass cabinet seemed to remain calm. However, Chen Nuo's spiritual power was receiving feedback from the octopus, and its consciousness seemed to be showing signs of growing restlessness!

The two submarines, one leading and the other following, advanced underwater.

With their searchlights turned on, Chen Nuo, observing through the window, occasionally spotted some fish and seabed coral reefs as the submarine glided across the ocean floor.

It felt like the submarine was descending along the continental shelf.

Moments later, a chaotic reef appeared on the continental shelf in front of them. The submarine swiftly navigated through, resembling a journey into a forest of chaotic underwater rocks.

The submarine had slowed down considerably, a clear test of the pilot's skills in this area.

At this time, Ishii Hisako finally seemed a bit tense, as Chen Nuo noticed her fingers gripping tightly.

Suddenly, Chen Nuo asked, "You've been down here before, haven't you?"

"Hm?"

Chen Nuo explained matter-of-factly, "You already know this place. Moreover… the octopus won't be needed for now. Which means we haven't yet reached the actual 'doorway'. I guess you've come down here more than once after discovering this place."

"Yes, I've been down a few times and reached that 'doorway.' I have even stood there," Ishii Hisako shook her head, "but I have never managed to figure out anything significant."

The pilot in front suddenly spoke up, "Entering radio silence in two minutes. Countdown begins!"

Ishii Hisako nodded. "Make the last contact with the surface, send the coordinates."

"Yes!"

Ishii Hisako then told Chen Nuo, "Below here, radio signals will be blocked, and other communication devices will fail—I don't know the principle, but it happens every time we come down here."

Past the underwater stone forest, a deep sea trench appeared before them.

The two submarines entered the trench, continuing to descend.

"Depth at 150 meters. Approaching destination," the pilot continued to report.

Chen Nuo looked out the window…

The trench was pitch-black now. The water outside was like a deep, dark space. In this place, it seemed that only the light from the submarine's searchlight was the sole source of illumination.

Just then, the pilot announced excitedly, "We've reached the entrance!"

The two submarines slowly adjusted their bearings in the water, then hovered at a certain position within the trench.

Chen Nuo immediately leaned forward, looking past the pilot to the front.

In the direction of the searchlight's beam, light shone on the trench's rocky walls, where schools of fish swarmed densely back and forth around a certain spot. Faintly visible was an oval-shaped, profound tunnel!

But inside, it was pitch-dark, impossible to see clearly.

"Fish are obstructing the way, launch sonar to disperse them," the pilot controlled the submarine while starting to report slowly.

The two submarines must have come down here multiple times. Although radio communication was impossible in this place, the cooperation between them was seamless.

The second submarine swiftly adjusted its position to follow behind the first one that Chen Nuo was in.

After the first submarine fired off a device resembling a sonar pulse, the dense mass of fish blocking the underwater tunnel entrance scattered in all directions as if startled.

"Enter!" The pilot's voice remained steady.

As they entered the tunnel, Chen Nuo felt the submarine shake slightly.

The tunnel was not very wide, but spacious enough for the submarine to navigate, though the speed had been significantly reduced.

He watched the tunnel walls intently.

The walls were uneven and pitted, appearing to be a naturally formed underwater tunnel. However, Chen Nuo couldn't shake the feeling that something was not quite right.

The tunnel twisted and turned, and the submarine reduced its speed to the bare minimum. Still, there were occasional light collisions against the protruding coral reefs on the tunnel walls, breaking them to pieces.

The submarine's outer shell was tough and specially treated. Since it was moving so slowly, these collisions caused no damage to the vessel. However, the vibrations from these impacts in such a narrow, sealed space at the bottom of the sea easily instilled fear and tension among the passengers.

Chen Nuo remained composed, but he was growing increasingly uneasy.

Throughout the tunnel, he did not stop releasing his spiritual power, constantly extending tendrils of it around the submarine, especially towards the front.

It was no exaggeration to say his sensory reach was even broader than the pilot's, who relied on instruments to navigate.

But as the tunnel delved deeper, Chen Nuo detected something strange.

The spiritual power he had released seemed to be bit by bit suppressed and pushed back!

What could initially detect a distance of twenty meters in front now slowly became compressed to... fifteen meters... ten meters...

The distance his spiritual power could perceive was getting smaller and smaller.

Chen Nuo also tried to increase the output of his spiritual power, but to his surprise, this place seemed to have an invisible force, akin to a shielding power, suppressing the perception of his Spiritual Telekinesis!

It was as if... the air and the water were becoming thicker and thicker, making the travel and movement of his spiritual power increasingly sluggish!

Eventually, the hull began to shake slightly.

The pilot seemed to breathe a sigh of relief. "We've reached the entrance! Prepare to surface."

As the submersible emerged from the water and left the tunnel, it entered a massive undersea space!

This appeared to be a waterless space created by a special balance of terrain and water pressure.

A huge, dome-like archway, over ten meters high.

After the two submersibles resurfaced, they stayed in the water next to a stretch of ground.

Once all the lights on the submersible were turned on, the originally pitch-black cavern was finally illuminated.

Chen Nuo sat in the submersible, looking outside...

The cave walls, probably corroded by perennial humidity, looked quite horrifying with jagged rocks, giving a sense of hell itself.

"Prepare the equipment, wear oxygen masks, and leave the ship!" Ishii Hisako took a deep breath and issued the command.

In this undersea cavern, the air was very thin, with an extremely low oxygen content.

The group left their seats and went into the cargo hold behind them, beginning to don oxygen tanks and masks.

"Each oxygen tank, when used, can last for two hours," Ishii Hisako said slowly. "If there's an emergency, you must immediately return to the submersible, which will stay here and then seal up. The oxygen stored inside the submersible will automatically refill... Remember, the moment your oxygen runs out, you must return! The air here has been tested. The oxygen content is very low; a normal person in such an oxygen-deficient environment would become incapacitated in no more than ten minutes! Oxygen tanks, each person carries two. One for the outward journey. Once the first oxygen tank is depleted, you must immediately return to ensure the second tank can support you getting back to the submersible. In other words, two hours' worth of oxygen for the journey out. Two hours' worth of oxygen for the return trip."

Chen Nuo chuckled. "Why not carry a few more oxygen tanks?"

"This is...taking into account the calculation of human load-bearing..." Ishii Hisako began but suddenly clamped her mouth shut.

Chen Nuo directly strapped two oxygen tanks to his body right from the cabin and then grabbed two more!

"I can carry four no problem," Chen Nuo laughed.

Actually, if it wasn't for the size of the oxygen tanks, with four of them on his back, there would be no space left... Chen Nuo actually could carry even more!

"Now, I need you to explain something to me," Chen Nuo said, watching Ishii Hisako strap two oxygen tanks to herself but then he grabbed the woman's arm.

Ishii Hisako's expression was stern. "What?"

"Ocean expeditions, research ships, submersibles, undersea tunnels..." Chen Nuo scoffed. "You've been hiding a lot from me. Before your Sect Hierarch made it big, he was just a simple masseur. Even if he got the octopus, how could he have managed to enter this place? If reaching this doorway is so troublesome... How did your Hierarch manage to get in all those years ago? Don't tell me he swam all the way here from the sea while holding onto an octopus!"

Faced with Chen Nuo's interrogation, Ishii Hisako showed no surprise.

By this point, it was time for such questioning to arise.

Ishii Hisako took a deep breath and slowly said, "I'm very sorry for hiding some things from you before... Your questions, naturally, I have answers for. But now is not the time to discuss them! In your presence, I am a weakling. As a weakling, of course, I need to have some chips for self-preservation! If I reveal all my cards to you at once, who's to say you won't just dispose of me and take over this place by yourself?"

Chen Nuo stared at Ishii Hisako's face, scrutinizing it for a long time.

"So even if I kill you and the others right now and proceed with the octopus on my own, it still won't do... There's more you haven't told me, right?"

"That's correct! It's just for self-preservation," Ishii Hisako said slowly. "Actually, there's no conflict between us. After we go in, we each take what we need. You are an Ability User, so the gains you can acquire will definitely far exceed those of us ordinary people."

After thinking for a moment, Chen Nuo put on his oxygen mask and nodded. "Let's go!"

The submarine hatch opened, and a line of people filed out.

Then two divers moved out a glass tank from the storage compartment, which contained the octopus.

The ground here was rugged, and the pulleys could no longer be used.

After a significant amount of water was released, the remaining water in the glass tank was barely sufficient for the octopus to survive.

The glass tank had been lightened as much as possible, and after the divers used a piece of equipment to carry it out, they began to transport it carefully.

Next to the cave, a dark tunnel lay, its destination unknown...

Chen Nuo glanced at this tunnel... It was just over two meters high.

The width was also just enough for two people to walk side by side.

The divers turned on their helmet lights, and a few beams illuminated the tunnel. Taking the lead were two divers, with Chen Nuo and Ishii Hisako following in the second row.

The four divers behind them, working in pairs, took turns carrying the tank.

The weight of the octopus, plus the glass tank and the water within, was close to thirty kilograms.

Two divers were assigned to carry the tank. Factoring in the weight of their own oxygen tanks and equipment, their progress as a duo was very slow.

Taking turns, each pair was responsible for five minutes, then switched to recover their strength.

After about three rotations...

The tunnel ahead suddenly opened up into a space that was slightly larger.

The tunnel had come to an end.

But in front, there appeared two pathways! One to the left, the other to the right.

Chen Nuo frowned.

"Bring it over here," Ishii Hisako breathed out.

This woman's breathing was somewhat unstable... after all, she had been injured just a few days ago, and now the weight of the oxygen tank was taking its toll on her body, as if she were forcibly enduring the pain.

The glass tank was moved to a position between the two entrances.

Chen Nuo started to frown.

He felt that his spiritual power became more sluggish as it wandered through the air...

It was as if an invisible force in the air was growing stickier, pulling from all directions at his psychic sensing.

Chen Nuo estimated that the range in which he could freely use his spiritual power was now no more than three meters around him.

Any further, and the released spiritual power would be controlled by an invisible force, dissipating instantly.

This place... seemed to be suppressing the range of telekinesis control.

Inside the glass tank, the life force of the octopus was becoming increasingly weak.

Chen Nuo approached it and could clearly feel that the loss of the octopus's life force had doubled in speed compared to before!

But as its vitality weakened, the octopus's mental consciousness seemed to strengthen somewhat.

That feeling of "invitation" was becoming stronger.

After making a round inside the glass tank, the octopus pressed itself against the right side of the tank, spread its eight tentacles, and suctioned its suckers onto the glass, but it clearly pointed in a distinct direction!

"Right side! Take the right path!" exclaimed Ishii Hisako excitedly.

The right side tunnel, upon entering, narrowed down!

Walking side by side was no longer possible, and they had to proceed in single file.

Chen Nuo didn't mind, but the divers behind him, tasked with carrying the glass tank, faced increasing difficulty, and their pace slowed even further.

Chen Nuo felt his spiritual power getting blocked and weakened once again!

The effective range of his psychic sensing was compressed to just two meters around him!

After reaching the end of the path, a decision once again lay before them!

This time, the pathway ahead split into four!!

Ishii Hisako rested for a few seconds, leaning against the wall to catch her breath.

"You'd better take a rest, you're using up your oxygen quite quickly," Chen Nuo said, frowning at the woman.

"I'm fine," Ishii Hisako shook her head. "I can hold on a little longer."

Repeating the process, they moved the octopus out to choose among the four pathways, relying on the Golden Octopus.

Suddenly, Chen Nuo asked, "If we don't use the Key, can we still enter? It's just a matter of choosing a path... If you bring more people, no matter how many forks there are, dispatching them to enter separately, you'd still be able to find the correct direction. Under those circumstances, the value of this Key seems to be nonexistent."

Ishii Hisako shook her head and said in a low voice, "That's not possible. The Sect Hierarch told me that if the wrong path is chosen here... there is an invisible force in control, a self-preservation mechanism. Once the wrong path is taken and entered, it might trigger a self-destruct device and then... everyone will be buried in this place."

Chen Nuo closed his mouth.

Though curious... it's better not to try such things.

At the second four-way junction, relying on the octopus's choice, the group entered the second tunnel on the left.

This time, they moved forward for about ten minutes...

The third choice had arrived!

This time, it was a choice of eight!

Exiting the tunnel, Chen Nuo looked up and couldn't help but breathe out a sigh!

It was a massive space!

This underground cave at the bottom of the sea had turned into a great dome nearly ten meters high here!

The wall in front had suddenly become smooth!

And beneath the cliff, there seemed to be a faint gold luster!

Chen Nuo squinted his eyes to look and took a deep breath!

Not just Chen Nuo, but Ishii Hisako and the other six divers also took a sharp breath!

On the wall that was ten meters high in front of them, despite the surface layer being eroded and transformed over an unknown number of years and the mottled wall, one could still see the metallic luster beneath.

And upon that metallic luster, when lit up bit by bit by the searchlights, a huge symbol could be discerned!

It was...

An octopus!

An oval head and body stood erect! Below it were eight tentacles spread out!

Each tentacle's end on the ground was an entrance to a tunnel!

Eight tentacles, eight tunnels!

Chen Nuo stood quietly, staring at the giant octopus symbol...

And the more he looked at the octopus symbol, the more familiar it seemed!

Although there were some slight differences in minor details and proportions, overall, the outline, the posture... it closely resembled the icon on the USB drive from the Octopus Monster website!

"Bring the box up," ordered Ishii Hisako, panting.

The glass box was lifted up...

However, this time, an accident occurred!

After the glass box was placed in the middle, the Golden Octopus in the water seemed to wriggle its body a few times and its tentacles appeared to twist twice... then, it suddenly stopped moving!

...

...

...

The several people looked at each other and waited for a while, their faces showing strange expressions.

Ishii Hisako, anxious, approached the tank and gently tapped the glass.

Chen Nuo walked beside her, frowning as he looked at the motionless octopus in the water.

Ishii Hisako's face showed urgency as she exclaimed angrily, "Move! Choose a path, quickly!!"

As she spoke, she increased the strength of her tapping on the glass.

Chen Nuo sighed, gently grabbed Ishii Hisako's wrist, and at the same time, he also withdrew a trace of spiritual power lingering around the octopus.

"Stop hitting it...

It...

Has already died."