The cave looked mostly the same as in the manga. Except for the circuit board patterns. They were different from what he remembered. But the general layout was the same.
"Wow~ A dark, scary environment. So black. I love it." Little Perona floated around, grinning.
"Don't wander too far, little Perona." Rhett walked into the cave. "Enel, discharge."
"100,000 volts!!!!"
Blinding lightning exploded in the cave. The current spread wildly through the circuit patterns on the walls. It was different from the original manga, but it still activated them. The entire cave was instantly illuminated by golden light.
"CRACKLE—BOOM!!!"
With a loud crash, the ground began to tremble. The patterns on the walls lit up like veins. Then—
"Click, click, click..."
Countless "little old men" robots sleeping in the stone walls suddenly opened their eyes. One by one, they stepped out of the walls! They blinked and turned to look at Enel.
"A miracle... It's a miracle!" Lieutenant Spaccy shouted excitedly. It and its three companions dropped to their knees and started kowtowing. "God Boss has appeared!!"
Tesoro looked at the ancient structure. "Captain, it seems we... accidentally activated an ancient city? You knew this would happen, didn't you?"
Rhett looked around. The blood mist stirred slightly. He had actually already spread his blood mist to every corner of the city. The corner of his mouth curled into an amused smile. "Interesting."
The entire cave gradually "awakened" under the stimulation of the electricity. The once pitch-black tunnel lit up with a soft glow. The circuit patterns on the walls pulsed like breathing.
Rhett was certain that these circuit patterns were not in the cover story. The ground shook more and more violently. Finally—
"BOOM—!"
Deep inside the cave, a giant stone door slowly rose, revealing the ancient city hidden behind it.
"Wow~" Perona floated in the air, her eyes sparkling. "So magnificent!"
The architecture of the city was strange. Tall spires and domed palaces were covered in circuit-like patterns. It was somewhat similar to Roman architecture. The streets were filled with activated little robots. They all turned to face Enel in unison. Their electronic eyes were full of reverence.
The little robots that had just appeared didn't have their memories straight. When they saw four robots dressed differently from them worshiping someone, they thought, "Oh, they're worshiping, so I should worship too."
"God Boss has appeared! Long live God Boss!"
Enel: "...? Why aren't they afraid of being shocked?"
Rhett looked at Enel and smiled. "Little toys. Power banks. Pfft."
Enel showed his shark teeth at Rhett. "Captain, you just said something very rude to this god, didn't you?"
"Welcome the return of the god—!"
The voices echoed through the city. It was indeed very spectacular.
Enel: "...Huh?"
Moria poked his head out of the shadows and grinned. "Kishishishi~ Enel, you really are a 'god' now. And these citizens of yours, in this place, they probably can't leave you. A god who is needed."
Enel's forehead veins bulged. "Shut up!"
Rhett ignored their bickering and walked toward a giant mural in the center of the city. The mural depicted winged moon people standing on a high platform, looking down at countless robot soldiers working. At the top of the mural was a line of ancient text.
"Birka — The Eternal City."
"Birka... Isn't there a Birka in the Blue Sea too?" Rhett muttered the name. He already knew what the mural showed. But seeing it with his own eyes was still impressive.
The mural recorded the history of this city in detail.
The moon people — who had wings on their backs and were very similar to the Skypieans — had built a highly advanced civilization here. They created countless robot soldiers to keep the city running. But as resources depleted, the moon people had to leave their homeland and find a new home on other planets. That is, the Blue Sea.
They built an island in the Blue Sea. Then they were carried up into the sky by a golden current. That created the two groups of people on Skypiea. And these robot soldiers were left here, waiting for a "god" to awaken them.
Of course, that was all Rhett's guess. Enel was probably the person closest to solving the mystery. Unfortunately, this "god" didn't seem interested in any of this. Or, to put it another way, if he did care, he wouldn't be Enel.
"So..." Tesoro rubbed his chin, deep in thought. "The Skypieans might be descendants of the moon people?"
Enel crossed his arms, looking annoyed. "Hmph. This god doesn't care about history!"
On the moon, Rhett was far less popular than Enel. It just went to show that solving the food problem was all it took to win people's support.
Just then, Lieutenant Spaccy suddenly came running, pointing excitedly at the depths of the city.
"God Boss! There's something there!"
Everyone looked in the direction it was pointing.
In the center of the city, on a high platform, floated a giant blue crystal. Something seemed to be sealed inside the crystal. It emitted an energy wave that made people's hearts race.
Rhett narrowed his eyes. The blood mist stirred silently. "It seems... we've found the real 'treasure.'"
"Enel, charge it. Quickly. Fully charged." Rhett stared at the blue crystal. "Let's see what treasure there is. Wow, is this the first time we've actually gone treasure hunting as real pirates? We've always just stolen things before."
Enel curled his lip. "Hmph. This god isn't some power bank..." Even as he said it, he raised his hand and released a blinding bolt of lightning.
"200,000,000 volts: God's Judgment!"
The moment the blinding lightning entered the crystal, the entire city of Birka shook violently. Fine cracks appeared on the crystal's surface. A pillar of light shot into the sky, illuminating the entire moon's surface.
Inside the pillar of light, an ancient stone platform slowly rose. Embedded in the center of the platform was a faint wisp of blood mist. Even though it was so faint it was almost invisible, Rhett could tell at a glance that it was his own blood mist.
"This is... my power?" Rhett's pupils contracted.
He had never been to the moon. But this life force definitely belonged to him. He could feel that his blood mist was keeping her alive. The circuit patterns around it were providing energy.
Rhett's first thought was, what had he done in the future? He really didn't remember.
A crystal coffin appeared on the stone platform. Under the transparent lid lay a white-haired girl. She wore a white dress. Her hands were folded on her chest. Her face was peaceful, as if she were just asleep.