Fishmen

More precisely, it was very much like radio communication.

In an open, unobstructed environment, radio signals could travel incredibly far. On Blue Star, shortwave stations could even use atmospheric reflection to establish communication across half the planet.

But underwater...

Theus looked around at the pitch-black seawater.

Underwater radio communication was extremely difficult. One could only use bands with especially long wavelengths and very low frequencies, along with many other restrictions.

For example, submarines using very low frequency (VLF) communication had to rise to reception depth to communicate, and they couldn't travel too fast.

Furthermore, submarine transmitters and antennas were enormous, taking up a considerable amount of crew space.

Yet neither he nor the Swollen Monster had any of that, and they could communicate without any obstruction while diving.

Theus turned to look at the Swollen Monster. If this telepathic communication worked on principles similar to the radio waves from his previous life, then the Symbiotic Pact was probably like tuning the two of them to the same frequency. On that band, there were only the two of them—a one-on-one connection.

But if a machine could locate that frequency and receive or transmit signals...

Theus drew in a sharp breath. The principles behind such a machine weren't all that complicated, and within moments, he'd already thought of a whole host of possible uses.

He'd really come to the right place this time, Theus thought to himself.

The Swollen Monster led him onward, diving into the distance. The light in the Deep Sea grew scarcer and scarcer, especially since it was night.

The water wasn't as clear as it was near the surface either. Visibility continued to worsen, and being able to see a few meters ahead was already decent.

At that moment, the senses granted by the Symbiotic Pact began to show their usefulness. That miraculous perception replaced his vision, allowing him to perceive everything around him with perfect clarity.

"...Could this be some kind of biological sonar?"

Dolphins could use echolocation, and they even emitted two interwoven sound beams at once, one high and one low, allowing for extremely precise positioning.

That was exactly what this felt like. He could observe the entire area surrounding him, centered on himself. He could even see through minor obstructions—such as a patch of seaweed ahead. He could clearly "see" the lobster completely hidden behind it.

Theus excitedly spun several circles in the water. This feeling was far too wondrous, an experience he'd never imagined before.

When he closed his eyes, the whole world became even clearer and brighter.

Theus had used similar things before. Vehicle-mounted radar could rapidly scan the surroundings and construct a 3D map, but it had never felt as natural and intuitive as this.

This Swollen Monster and the Symbiotic Pact had truly brought him too many surprises. Whether these sensory abilities were physical or magical, they had countless potential applications. Even on technologically advanced Blue Star, they could trigger a technological revolution that swept the globe. And now...

Let this world witness the shock of Castel Island!

Theus couldn't stop the corner of his lips from curling upward.

After following the strange fish for a long time, it gradually slowed down, and Theus sensed that something was wrong.

The smell of blood.

He'd never known what the scent of blood was like in the sea before, but now he saw it—like paint splashed across the ground, glaringly announcing its presence.

In the distance, several sharks swam about faintly, yet for some reason, none dared approach.

"What's going on?" Theus asked the Swollen Monster in his mind.

"Something's wrong. The Fishmen seem to be fighting."

"Fishmen?" Theus was startled. Several images swiftly formed in his mind, and soon enough, he saw what the Fishmen looked like.

Creatures with fish heads, carrying all kinds of weapons, swam toward them from afar.

Though they were called Fishmen, they possessed none of the traits of humans. They were more like large fish that had grown limbs.

Their heads were disproportionately huge, their mouths packed with sharp teeth, while their arms and legs appeared slender. They swam by undulating their bodies through the water, their webbed limbs serving only to maintain their posture and change direction.

The Swollen Monster pulled Theus into a nearby coral reef to hide.

The Fishmen's senses didn't seem particularly sharp. They failed to notice the two of them and instead swam in the same direction.

"They appear to be fighting my kin."

Theus raised a brow. So the two races were enemies?

Thinking back to how it had said its people were "trapped in the shallows," perhaps that had something to do with these Fishmen?

Theus voiced his doubts through the Mind Link.

The Swollen Monster nodded. "Your guess is correct. My people have always been enslaved by the Fishmen."

Theus looked at the Swollen Monster's enormous body, then glanced at the Fishmen swimming in the distance. In terms of sheer size, several Fishmen combined couldn't compare to this monster.

"The Fishmen greatly outnumber my people. Most of our strength is spent resisting the water pressure. To gain the chance for a Symbiotic Pact, we can only submit to Fishman enslavement."

It paused before continuing.

"I don't know what the Fishmen did, but my people have begun fighting them. I had originally planned to sneak in, tell them the truth about the water pressure, and then persuade them to head into the Deep Sea together in search of a home..."

Theus could feel the conflict within the monster before him. It didn't want him to enter danger, but it was also worried about its kin.

"Let's go take a look at your people. We'll be careful."

After hesitating, Theus still decided to follow. If he left them alone, these Swollen Monsters with Transcendent abilities might all perish. They had only been enslaved because they couldn't defeat the Fishmen in the first place.

Besides, this was not far from Castel Island. Leaving them alone would ultimately pose a hidden danger. Without the Swollen Monsters' help in the future, he'd have to deal with the Fishmen himself.

Come to think of it, it was rather strange. He was the lord of Castel Island, yet he knew absolutely nothing about these underwater Fishmen.

Whether as Duke Cohen's illegitimate son or as a vassal of Her Majesty the Empress, that was somewhat odd. No matter how hard he searched his memories, he couldn't find any relevant information.

Did the Empire know nothing about these underwater Fishmen either? They were practically on its doorstep.

Had these Fishmen lived in the sea for years and never interacted with the outside world, or was there some other reason?

Theus narrowed his eyes.

"Master, Ash will protect you with his life," the Swollen Monster said gratefully.

"Ash? Is that your name?"

"Yes. It means... Ah, it's my people!"

Ash's voice became far more urgent as he pointed forward with one arm.

Theus looked up, then immediately frowned.

The seawater there was murky. Blood and severed limbs churned through the water, drawing swarms of sharks that watched from afar.

Many Swollen Monsters like Ash, their bodies and limbs twisted and distorted, were fighting the Fishmen.

So this was Ash's people—the Swollen Monsters who called themselves The Cursed.

Theus looked carefully. At a glance, The Cursed all seemed distorted in different ways, but upon closer inspection, it was possible to distinguish their original limbs.

Their normal forms might be impossible to make out, but at least their number of limbs could be determined. They seemed to have more than one pair of arms, and unlike the Fishmen, their limbs weren't so slender as to seem deformed.

Most Fishmen wielded crude weapons. A few carried metal harpoons, though they were all covered in rust.

Whenever they opened their mouths, they revealed rows upon rows of sharp, jagged teeth like sharks'.

Most of the Swollen Monsters fighting the Fishmen were empty-handed. A few held weapons seized from the Fishmen. Though the Fishmen vastly outnumbered them, they were steadily being driven back.

That was because these Swollen Monsters didn't rely on physical combat alone. Their swollen, twisted limbs formed strange gestures, unleashing all manner of wondrous magical effects.

Black ice spikes, enormous water bullets, or even great swarms of sea snakes surged madly toward the Fishmen.

Transcendent power!

Theus felt his heart begin to pound.