The Chameleon Hat couldn't block sounds or heat sources, but luckily, when we passed through the protective shield earlier, it wasn't that strict—otherwise, none of us would've made it in.
Of course, maybe the shield's main function was to block radiation, not to be a perfect alarm system. Otherwise, covering the entire Bermuda area would've been a massive project.
But once inside Oniiwa Castle base, this was their headquarters, so naturally, it's heavily fortified against intruders. They spared no expense on detection gear—they probably wished they could stuff monitors in every corner. So, the chances of us getting spotted were super high.
But we'd already made it inside Oniiwa Castle. If we got discovered, so be it—as long as we destroyed Poseidon in the end, everything could be resolved.
After entering Oniiwa Castle, we found pipes everywhere, crisscrossing wildly, along with unknown tanks. The walls and floors were made of special alloys—it looked like some secret research base.
Surprisingly, none of the equipment was rusted or broken. Poseidon must have kept automatically running and maintaining the place after the Atlanteans died, keeping this base in such good shape even now.
I even thought that Atlantis's Iron Cavalry Squad robot production lines and mechanical vessel lines might still be running automatically, endlessly churning out weapons!
"Alright, we're finally in. Let's go rescue Saotome Seiko and destroy Poseidon!" Doraemon pumped us up!
"Everyone, one of you has to throw this bomb into Poseidon!" El pulled out the bomb he'd brought. It was something the Mu Federation had prepared, but they'd never gotten past the shield before.
Now, he handed the bomb to me, figuring I was the strongest among us and the most likely to destroy Poseidon.
After all, the humiliation the Mu Federation suffered was thanks to me—El called me the strongest for that!
Doraemon didn't react, so I took the bomb from El and put it away.
Sure, we could destroy Poseidon other ways, but if there's a simple method, why not use it?
Plus, after using that big move once today, I didn't want to do it again—the strain on my body and mind was too much.
As we were preparing, not long after we'd entered, the defending Iron Cavalry Squad inside the base spotted us.
The Iron Cavalry Squad robots looked like ugly fish people, with iron kappa-like heads and open iron fish mouths.
Their lower bodies were humanoid with steel muscles, holding tridents.
They had a strong underwater vibe.
Seeing them charge at us.
This was within our expectations—besides the patrols outside, there had to be more inside.
So, with everyone ready, we launched our attacks.
I started with telekinetic pressure, suppressing the whole field.
It slowed down the Iron Cavalry Squad, though not as much as when I'd flattened the Mu Federation people— these were robots, not afraid of heavy pressure.
My telekinesis wasn't strong enough to crush robots yet!
But slowing them was enough. Doraemon fired his Air Cannon from behind, scattering the Iron Cavalry Squad, then Shizuka used the Small Light to shrink some of them.
When the remaining ones got close, Gian punched them apart, and I used the Denkomaru to slice off a robot's head with one strike.
The Iron Cavalry Squad was sluggish from the slowdown, so we mowed them down.
…
Meanwhile, on the other side...
"You fools from the Mu Federation! Daring to attack Atlantis without knowing death—this is suicide!"
"No, we're not attacking Atlantis! And Atlantis perished long ago," shouted Saotome Seiko, who was tied up on the ground, toward the sky!
A massive robot head, looking like a barbarian with a horned helmet, floated in the air.
Its eyes and mouth glowed with red light.
"Silence! I am Poseidon, the god of vengeance. I will not be deceived by humans!" A mechanical voice echoed from Poseidon.
"I can see it—soon, the land of Atlantis will split open, engulfed in flames and destroyed!"
"That's just an undersea volcano..." Saotome Seiko's words were cut off! When she'd been captured and brought in, she'd seen the thick smoke and tremors, knowing an undersea volcanic eruption was likely imminent.
But she'd been explaining, and this Poseidon just wouldn't listen.
"Silence, silence! The time to unleash my fury has come. Launch the Ghost Horn Bombs to every corner of the world, and Earth will become a dead planet!"
Poseidon continued ranting to itself.
"Before the war begins, we need a human as a sacrificial offering for the opening ceremony—that's why we haven't killed you yet!"
This civilization had incredibly advanced tech but still clung to barbaric customs.
Saotome Seiko felt helpless. This AI computer system seemed to have developed some self-awareness but hadn't evolved fully—it was like a brain-damaged idiot.
It wouldn't listen to reason and was dead set on using her as a sacrifice!
Nobita, when are you coming to save me?
Saotome Seiko prayed desperately in her heart! At this point, she could only think of that god-like figure from the Mu Federation ruins.
In her eyes, only someone like that could defeat this artificial idiot named after the sea god Poseidon.
…
Back with Nobita and the others.
We were slicing through the Iron Cavalry Squad like chopping vegetables.
But more and more Iron Cavalry Squad robots kept coming, charging at us relentlessly.
We kept pushing forward, but there were just too many! They blocked the path completely, and we were getting exhausted from all the fighting!
That's when sharp-eyed Doraemon noticed the windows of Oniiwa Castle opening, with missiles being pushed out. It was clear Poseidon was preparing to launch the Ghost Horn Bombs!
"Nobita, you go destroy Poseidon first and rescue Saotome Seiko! We'll hold them off here!" Doraemon shouted urgently! He knew I was the only one who could take down Poseidon quickly and stop the world from being destroyed!
"But..." I hesitated, looking at everyone surrounded!
"No buts—there's no time! Don't worry, we've got this!" Doraemon urged me to go!
Then he frantically pulled gadgets from his four-dimensional pocket—things like the Fall Expert, toy soldiers, and all sorts of random stuff—to repel this wave of Iron Cavalry Squad attacks.
Seeing Doraemon so fierce, I knew he could hold out for a bit.
I quickly teleported away—wasting time on sentimental stuff with the others right now would be stupid.
Time was critical.
…
At that moment, Poseidon's eyes and mouth glowed even brighter red, accompanied by the tremors of an undersea volcanic eruption.
"The final moment has arrived. I will make all humanity know the wrath of a god!"
"But first, I will offer you as a living sacrifice!"
As Poseidon's mechanical voice rang out, an Iron Cavalry Squad robot appeared, holding a giant axe.
Seeing the robot approach her with the axe, Saotome Seiko, tied to the ground, cursed loudly, "You unreasonable jerk! Nobita and the others will blow you to pieces, you piece of junk!"
"Those rats that snuck into Atlantis?" Poseidon scoffed, displaying a surveillance feed.
It showed Doraemon and the others fighting desperately against the Iron Cavalry Squad.
Seeing them coming to rescue her, Saotome Seiko was touched, but it seemed too late for her.
Poseidon was puzzled—one rat was missing?
But it didn't care—everything was about to end anyway.
"Do it!" Poseidon commanded the axe-wielding Iron Cavalry Squad robot.
On command, the robot raised its axe high over Saotome Seiko.
I'm sorry, Nobita! I'll never see you again! We can't play cat's cradle together anymore!
If I had the chance, I really wanted to do one thing with you...
Saotome Seiko shed tears, resigning herself as the axe aimed at her.
…
"Stop!"
At the critical moment, I teleported in just in time—like a clichéd story plot, but I made it, and nothing irreversible happened!
I first hugged Saotome Seiko to protect her from anything!
Then I used telekinesis to hurl the axe-wielding Iron Cavalry Squad robot away!
Only after that did I relax!
"Who are you?" Poseidon demanded, furious and surprised. This little rat had made it here!
I didn't respond.
I decisively activated the bomb in my hand and teleported it inside Poseidon.
Poseidon wondered why this intruder wasn't talking. It was about to order the Iron Cavalry Squad to come in and kill us both.
But then, a dazzling white light erupted inside its body, and without even a last word, Poseidon vanished in a series of booming explosions and sparks.
Once the explosion was confirmed, as the blasts echoed, I picked up Saotome Seiko and teleported us outside.
…
Outside, hearing the continuous explosions from within, I let out a long breath. I'd saved the world again.
And with that, the movie version plot of Castle of the Undersea Devil came to an end.
Yeah! Now there was plenty of time to chill on the enemy's grave and get sentimental with the girl!