As Pomby gazed at these colored circles, he felt a mysterious power enveloping him. The seven colors of the rainbow seemed like a mystical code, a key connecting him to this underwater city.

When Pomby attempted to step onto the red circle, he felt a wave of warmth washing over his soul. Next, stepping onto the orange circle, he suddenly felt invigorated, as if the orange circle bestowed upon him infinite strength.

Then, Pomby sequentially stepped onto the yellow, green, blue, indigo, and violet circles, with each different color circle providing him with distinct positive sensations and feedback. Every step Pomby took seemed to activate different mechanisms within the city.

When Pomby stepped onto the final violet circle, after a few seconds, the entire plaza was suddenly enveloped in a radiant semi-spherical glow. Standing in the light, Pomby felt an inexplicable comfort and tranquility, as if this underwater city was conveying some mysterious message. Within the illuminated area, seawater rapidly drained away, leaving behind a dry space.

At this moment, the entire circular plaza began to rotate while descending, stopping after about twenty meters. Pomby’s surroundings brightened, and he realized he was in a space roughly the size of ten football fields.

The space was well-lit, allowing Pomby to see the vast emptiness. However, on the distant side of this space, there was an object that looked like a blue whale, stationary.

Pomby instinctively wanted to approach and see what it was. With no seawater in this space, he removed his diving equipment and carried it, slowly walking towards the distant end, heading towards the object that resembled a blue whale.

After about ten minutes, Pomby finally reached the front of the blue whale-shaped object. He carefully circled around it, examining it closely, and discovered that it was likely a ship, just shaped like a blue whale. The vessel appeared to be made of some advanced high-tech alloy, emitting a subtle metallic sheen.

Standing in front of the blue whale-shaped vessel, Pomby felt excited about this unexpected discovery. He observed the vessel closely, wondering if it could be a battleship.

Pomby noticed a seemingly control panel on the outer shell of the vessel. He gingerly touched it, and suddenly, the entire vessel emitted a faint vibration. Lights shimmered across the hull, and the vessel radiated a gentle blue glow.

The outer shell of the vessel opened, revealing a passage leading to what seemed like a spacecraft cabin. Pomby decided to enter this mysterious compartment. As he stepped inside, the cabin door closed behind him. Walking through the interior passage, Pomby reached a section that resembled a command control room, with a large transparent glass panel providing a view of the outside. In the middle of the command room was a comfortable chair, and Pomby thought this must be where the captain sits, so he sat down.

After settling into the chair, the ship’s interior suddenly echoed with a voice, “Welcome aboard, Captain Pomby.”

Startled by the unexpected voice, Pomby didn’t understand how the ship knew his name or why it referred to him as captain. He attempted to stand up but found himself restrained by a safety harness. He struggled to break free, but it was futile.

“Please don’t panic, Captain Pomby,” the voice continued, “I am Alpha, the artificial intelligence system of the Blue Whale-class battleship. Allow me to explain everything to you.”

Pomby was both astonished and puzzled by the voice. He didn’t understand the current situation.

Next, Alpha, the artificial intelligence system of the Blue Whale-class battleship, explained to Pomby that it could scan his brainwaves, allowing it to know his name and communicate with him in his language.

Somewhat surprised, Pomby responded excitedly, “How is that possible?”

“Our technology possesses powerful telepathic capabilities, enabling us to read your thoughts. It is an advanced technique and one of the legacies of an ancient civilization,” explained Alpha.

Alpha continued to elucidate the control system of the Blue Whale-class battleship. Upon receiving commands from the captain, Alpha automatically analyzed and made optimal decisions to control and drive the entire battleship. Therefore, there was no need for additional crew members on the battleship; as long as there was the artificial intelligence system Alpha, it could handle all tasks.

Alpha further explained to Pomby that the Blue Whale-class battleship had been docked here for five thousand years since the disappearance of the ancient civilization in the underwater city. When designing the Blue Whale-class, the internal program was set to initiate the latest mission each time the ship was activated. Failure to perform the current mission would disrupt the entire operational system of the vessel, affecting the balance of the surrounding environment. Therefore, now that Pomby had activated the Blue Whale-class battleship by boarding it, it had to execute a mission assigned by the central computer system.

Pomby asked Alpha, “Can’t you cancel this mission?”

Alpha replied that it wasn’t possible because it was set up when the Blue Whale-class battleship was built, and it didn’t have the capability to cancel the mission.

Pomby suddenly felt a bit trapped, but it seemed like he had no choice but to reluctantly accept the mission.

Next, the Blue Whale-class battleship slowly rose from the vast underground space, moving towards the circular plaza where Pomby first arrived. After reaching above the main plaza, the battleship descended and settled on the circular plaza. The entire circular plaza began rotating and ascending, returning to the area of the palace where Pomby initially arrived.

At this moment, the previously enveloping semicircular light screen slowly disappeared, and seawater began rushing in. Soon, the entire Blue Whale-class battleship was submerged in the seawater.

Pomby asked Alpha about the next mission. Alpha replied that the central computer had not collected the latest data yet, and the detailed mission information would be provided later. However, the Blue Whale-class battleship had to leave the underwater city first and cruise into the depths of the ocean. During the journey, the central computer would plan the mission based on the latest environmental conditions.

The Blue Whale-class battleship slowly ascended, and the water curtains of the underwater city shimmered in its presence. Pomby sat in the captain’s seat on the bridge control center, facing a mysterious underwater scene. The powerful engines of the Blue Whale-class battleship emitted a deep roar, creating a solemn and mysterious atmosphere permeating the surroundings. The battleship stretched its massive body in the water, awakening like a long-dormant giant.

The Blue Whale-class battleship began to move forward, quickly leaving the ancient underwater city ruins and heading into the depths of the sea.

The ocean, vast and expansive, covers over seventy percent of the Earth’s surface. Viewed from space, the Earth appears as a spherical orb with intricate blue patterns.

The Earth’s structure consists of a magnetic core, flowing mantle, and a solid lithosphere. The lithosphere comprises the crust and a deeper outer shell mainly composed of solid mantle. The crust beneath the continents is known as continental crust, while beneath the deep sea lies oceanic crust. The oceanic crust is primarily composed of relatively dense basalt with a thickness of approximately 5 to 10 kilometers.

The seafloor conceals many volcanoes that erupt and create new geological structures. In the deep sea, magma continuously erupts, rapidly cooling and solidifying into various peculiar rock formations. These newly formed volcanic rocks form the base of underwater volcanoes, creating a new foundation for subsequent volcanic activities. With the compression and friction of tectonic plates, earthquakes may occur. Undergoing processes of growth, activity, and subsidence, some underwater volcanoes can even grow above the sea surface, forming volcanic islands.

At the boundary between oceanic and continental plates, the denser oceanic plate slides beneath the continental plate, forming a trench, while the overlying continental plate deforms, bends, and gives rise to mountain ranges accompanied by seismic activity.

The Mariana Trench, extending 2,500 kilometers on the ocean floor near the Mariana Islands, holds the record as the Earth’s deepest trench. Despite its average width of only 68 kilometers, the trench reaches a depth of 10.994 kilometers below sea level.

The ocean, one of Earth’s most mysterious and richly diverse ecosystems, evokes awe with its majestic landscapes and vibrant biodiversity. Under the radiant glow of the Blue Whale-class battleship, Pomby looked through the reinforced glass in front, marveling at the breathtaking underwater scenery.

The underwater world resembled a magical garden, with colorful coral branches and leaves emitting radiant light under the influence of sunlight. In the deep blue seawater, the Blue Whale-class battleship illuminated the underwater wonderland, creating a soft and dreamy effect. Against this blue backdrop, the coral gardens resembled a colorful castle. Lights scattered on the coral branches and leaves, each piece surrounded by gem-like brilliance, creating a dazzling display akin to a vibrant fireworks show. Various beautifully colored fish gracefully moved through the coral branches—golden butterflyfish, deep purple triggerfish, and blue conches—all appearing like elves frolicking in the coral garden, infusing vitality into the underwater world.