As our submarine got closer to Oniiwa Castle, everything around us became darker and more desolate. Even the Mariana Trench wasn't this pitch-black.
"That's the dark world enveloped by the protective shield—Atlantis!" El said, his eyes fixed ahead with a serious expression.
When we first arrived near Oniiwa Castle, we all looked outside and were totally shocked!
"What a terrifying number!" Suneo exclaimed in awe!
Suddenly, a bunch of Oniiwa Castle submarines appeared. They were not only bigger than the Mu Federation's subs but also way more numerous.
If Atlantis hadn't messed itself up and collapsed, the Mu Federation might not have stood a chance against them.
We had no choice but to get out of the submarine and find a spot to hide from the patrolling Oniiwa Castle subs.
"It's probably because we're approaching their territorial waters," El explained.
"Is that under Poseidon's control too?" Doraemon asked curiously. Wasn't that computer only supposed to control the Ghost Horn Bombs?
"No, those are mechanical vessels that just search for enemies. Even though the nation perished a thousand years ago, they're still wandering the ocean floor," El said with a sigh of regret.
Doraemon carefully released a probe, but as it drifted forward and approached the protective shield, it was suddenly hit by an attack. A massive bolt of lightning erupted from the impact point, startling all of us.
Their defenses were still tight! It got spotted the moment it floated up there.
Then, the alerted Oniiwa Castle patrol forces started heading our way.
"What do we do next? There are so many Oniiwa Castle subs patrolling," Suneo asked.
"Watch this!" Doraemon said with a smile, pulling a hat out of his four-dimensional pocket.
"Chameleon Hat!"
"You can see outside from inside, but they can't see us from outside!"
Doraemon quickly tossed the hat on the ground, and it grew bigger. He urged everyone to get inside.
Once we were all in, Doraemon pressed a switch inside the hat, and it vanished from sight.
Then, when Doraemon pressed another button, a transparent skylight appeared overhead.
We watched as the Oniiwa Castle patrol forces checked the area and left empty-handed, and we all breathed a sigh of relief.
"This gadget is amazing!" El said in amazement, seeing how the forces couldn't spot us.
"That's not all!" Doraemon replied, leading us forward.
As we walked, the transparent skylight moved with us.
It turned out the hat could move along with the people inside.
"Alright, let's head toward Oniiwa Castle!" Doraemon encouraged.
We picked up the pace and soon approached the protective shield.
But everyone was still a bit on edge—we remembered what happened to the probe.
"We're about to reach the protective shield. If it extends underground, can we pass through safely?"
"What if we touch it and cause a huge explosion? We'd be done for!"
Suneo sounded uneasy!
Everyone's hearts were in their throats.
Shizuka unconsciously grabbed my hand and squeezed it tight.
I didn't say anything, just squeezed back.
As we slowly crossed the protective shield, the expected explosion didn't happen.
Our anxious hearts settled, and we let out a long breath, feeling a surge of relief.
"Anyway, we've finally snuck in!"
"So, where exactly is Oniiwa Castle, and where is Poseidon located?" Doraemon turned to ask El.
"I don't know!" El replied.
"You don't know?" We all stared at him with wide eyes!
"There's no helping it. We've sacrificed so many people in the past, and hardly anyone has made it through the protective shield, let alone reached the temple where Poseidon is stored! That temple is guarded by the Iron Cavalry Squad—it's basically a one-way trip. No one's ever seen the temple and come back alive!" El said helplessly.
"Temple? Iron Cavalry Squad?" We asked, confused!
"The temple is a place to worship gods, just like how we in the Mu Federation worship the god Nabala. Poseidon is there, and the Iron Cavalry Squad is a legion of robot knights that guard it," El explained his helplessness!
No matter how advanced a civilization is, they can't escape spiritual reliance. I thought about how these two advanced underwater civilizations still believed in gods.
Of course, I didn't feel like digging deeper into it. There are too many weird things in Doraemon's world.
Who knows what's real or fake? Like that prophecy from Bauwanko I in the Giant Idol battle—who knows how he pulled that off?
So, it's best to respect ghosts and gods from afar—as long as they don't mess with me, I won't go looking for them.
While I was thinking about this...
"Looks like we'll have to rely on my gadget!" Doraemon said, rummaging in his pocket and pulling out a staff.
"Missing Person Stick!"
"Just say the name of the person you're looking for, and the direction it falls will show you their approximate location!"
"Since Saotome Seiko was captured, if we locate her, we can follow the trail to Poseidon!"
With that, Doraemon said Saotome Seiko's name into the Missing Person Stick.
"Alright! It's this way!" Seeing the direction, Doraemon urged us to head that way.
As we walked, I finally got a real look at the true face of Atlantis city.
Houses that were as tall as skyscrapers on land were now rundown, covered in thick layers of mud and dust, with faint outlines visible. The place was empty, streets littered with all sorts of debris and unknown objects.
There were even wreckage of planes and ships—probably from those who vanished in the Bermuda Triangle—now buried under thick sand.
It felt like a dead city.
Walking through this city, we all felt a pang of sorrow. This was the image of doomsday after a nuclear war.
"This must have been a huge metropolis thousands of years ago!" Doraemon sighed at the passage of time and the burial of civilization.
"If there's a hell, it must look like this!" Shizuka said fearfully, gripping my hand even tighter!
I felt helpless—it's like how a tough girl who could crush a skull with her bare hands can't open a bottle cap!
As we passed through this dead silent city, we arrived at a bizarre cliff.
It was a cliff shaped like a devil's skull—probably an entire underwater mountain hollowed out and turned into a base.
This had to be the real Oniiwa Castle.
The temple storing Poseidon should be inside!
We had just gotten close when we spotted lots of patrolling Iron Cavalry Squad soldiers in Oniiwa Castle.
Some were even staring straight in our direction.
Seeing this, we all held our breaths, afraid to make a sound.
Doraemon quickly pulled out a mole robot from his pocket—no time for explanations.
He released it underground, and it dug off in the opposite direction from us.
The noise it made drew the Iron Cavalry Squad away from the entrance.
"It won't work anymore—inside Oniiwa Castle, this hat can't hide us!" Doraemon urged us to hurry in while the Iron Cavalry Squad was distracted.
We rushed out of the hat and scrambled into Oniiwa Castle.