It had been nearly three hours since their ship left Tidehaven. The sea, initially calm, slowly grew wider and quieter. There were no longer any village voices, rows of houses, or birds that usually flew low along the coast. All that remained was the sound of the ship's engine and the waves rhythmically pounding against its hull.
Ganendra sat at the side of the ship, staring at the horizon. Every so often, his hand touched the sword hanging at his waist, making sure it was still in place.
“Can you stop checking your sword every five minutes?”
Ganendra turned around, while Oba remained focused on the wheel.
“I’m just making sure.”
“Making sure of what?”
“That my sword hasn’t disappeared.”
Oba rolled his eyes. “If your sword disappeared, I’d be the first to notice. There are only two of us on this ship.”
Ganendra fell silent. “You’ve got a point.”
Oba chuckled. “Sometimes I wonder how someone like you ever became a Rank B adventurer.”
“What do you mean?”
“You’re strong, but you overthink things that don’t need thinking about.”
“And you talk too much about things that don’t need talking about.”
“Hey!” Oba glared sharply at the indifferent Ganendra.
Ganendra turned his gaze forward again. This time, he noticed something.
The seawater around the ship had begun to change color. The bright greenish blue it had been before was slowly turning darker.
“We’re getting farther from the coast,” Ganendra said.
“Yeah, that’s right.”
“And you’re still sure you know the way?”
Oba immediately turned around, looking offended. “Of course! I’ve come to this area many times.”
“Many times?”
“Yeah. I used to come here often when I was a kid.”
“What for?”
“That’s a secret.” Oba chuckled at Ganendra’s sour expression.
A short while later, Oba turned off the ship’s engine.
Ganendra frowned. “Why are we stopping?”
“We’re here,” Oba said, standing up and pointing at the surface of the sea.
Ganendra examined the spot Oba indicated. There was no island and no ship. Nothing existed there except the vast ocean.
“Where’s the cave?”
“Under us.”
Ganendra stared at Oba in confusion. “What?”
“The cave is on the seafloor.” Oba pointed at the sea again. “Take out the Nerea leaves. We need them.”
Ganendra pulled two Nerea leaves from inside his robe and held them out to Oba.
“Now listen carefully. But first, chew this leaf,” Oba said, handing one of the Nerea leaves back to Ganendra. He had already eaten his portion.
The bitter, minty taste of the Nerea leaf made Ganendra grimace slightly.
“First, Nerea leaves only last for three hours.”
“What do you mean?”
“After you eat a Nerea leaf, you can breathe underwater without worrying about your lungs filling with water.”
“All right, I understand.”
“Second, we can only communicate through telepathy. That’s the leaf’s other function.”
Then Oba spoke inside his mind while staring at Ganendra. ‘Can you hear my voice?’
‘Yes, I can hear you,’ Ganendra replied in his mind.
“And third...” Oba’s previously serious expression changed. His brows drew together, and his eyes shifted toward the sea, as though he were watching something unusual down there. “Please protect me from ‘him’ chasing us.”
“What do you mean? Who is he?”
Oba shook his head. “It’s hard to explain. You’ll understand what I mean later.”
Ganendra sighed. “All right, I understand.”
The two of them looked at each other and nodded. At the same time, the sound of rippling water rose as Ganendra and Oba entered the sea.
“Can you swim faster?” Oba asked.
“Yes, I can.”
“Okay. Remember, we only have three hours.”
As they began diving deeper, the condition of the seawater changed drastically. The water grew murky with tiny, glowing particles swirling through it, stirred up by the activity of a gigantic creature below them.
When they were nearly at the seafloor, where the cave was located, they were confronted by a group of giant octopuses as large as houses. Strangely, however, they did not attack, and Ganendra sensed no killing intent from them at all.
“Ah, I hate you guys!” Oba complained as he swam closer to Ganendra. “Please protect me from them, especially the one that’s bigger than the others.”
“What are they? They look almost like Krakens, but they’re much smaller.”
“They’re definitely different. They’re giant floating octopuses. They aren’t dangerous, but their constant curiosity about anything—or any newcomer—is a real pain.”
“What do you mean?”
“They’re like giant cats that love clinging to your legs. Except they’re the sea-creature version.”
The group of giant octopuses moved slowly, the flapping of their bodies creating localized whirlpools that tossed Ganendra and Oba around helplessly. Oba’s face went pale when he saw the giant octopus’s tentacles moving toward him. Fortunately, Ganendra swam quickly, pulling himself away from the whirlpool created by the monster.
“Swim down quickly. The cave we’re heading for is not far from here,” Oba ordered, occasionally glancing back at the group of octopus monsters still chasing them.
With one powerful kick, Ganendra swam deeper into the sea, pulling Oba along with him. In the distance, he could faintly make out a cave that wasn’t very large. Unfortunately, the cave was sealed by a massive stone resembling a door.
“Destroy that cave door before they get here!” Oba ordered in a panic.
Ganendra drew his sword and slashed at the door with a powerful swing, but it remained firmly in place. Seeing that, Ganendra swung his sword wildly at the cave door.
Just as Ganendra was nearly ready to give up on finding a way to open the cave door while surrounded by the troublesome octopus monsters, Oba realized something. The circular carvings on the cave’s stone door bore geometric symbols exactly identical to the gemstone set in the ancient ring Oba always wore.
Oba brought his hand close to the cave door, and suddenly, a bright beam of light enveloped them. Soon afterward, the cave door shook violently and opened on its own.
With the last of his strength, Oba held his position in front of the cave entrance, keeping the ring’s vibrations from letting the door close again while protecting it from the grasping tentacles of the curious monsters.
“Ganendra! Get inside!” Oba ordered.
Ganendra shot through the gap in the door and into the cave, using his body to cut through the underwater current as he reached for the heirloom sword before the energy in Oba’s ring ran out.
Ganendra gripped the heirloom sword’s hilt and pulled it free with one powerful jerk, completely breaking the ancient magical seal inside the cave. The sword did not emit fire or lightning. Instead, it released a deep purple sonar shockwave. The wave traveled thousands of meters in every direction through the water, creating a heavy pressure pulse without damaging the cave’s structure. At the same time, the blade radiated the aura of an apex predator—like the gaze of a ruler of the sea awakened from a thousand years of sleep.
No longer caring about Ganendra and Oba’s presence, the house-sized monsters immediately collapsed their bodies, blasting out a massive volume of water before shooting backward into the darkness of the deepest ocean trench at incredible speed.
The cave door, which Oba’s ring had been holding open, remained open. It was as though something inside the cave had recognized Ganendra’s presence. Ganendra emerged from the cave holding the faintly glowing sword. Outside, the deep sea, which had previously been dense and chaotic with the giant octopus monsters surrounding them, was now utterly still, silent, and empty. Not a single sea creature dared approach within a radius of several kilometers.
The evening sun greeted them as their heads broke through the calm surface of the water. They were both breathing heavily, but relieved laughter broke through the slap of the waves. Ganendra helped Oba climb onto the deck of their wooden ship, then pulled himself up with the last of his strength.
On the warm deck, Oba immediately lay on his back and stared at the sky while massaging his fingers, which were still red from the ancient ring’s resonance.
“I swear, I’m never diving again if I have to run into them,” he grumbled with a wide grin.
Ganendra chuckled and set the heirloom sword beside him. Strangely, the sword was completely dry after emerging from the water. Its dark black blade now reflected the orange light of the setting sun, and the terrifying deep-sea predator aura from before had changed into a soft, soothing hum—as though the sword had accepted Ganendra as its new master.
Oba sat up, looking back and forth between the sword and the ring on his finger. “Not a bad partnership for someone who can’t fight, huh?”
Ganendra proudly patted Oba on the shoulder. “Without your ring and your brains, we’d have been giant octopus toys down there until next year.”
Oba turned the ship’s wheel, leaving the calm sea behind as he prepared to bring the heirloom sword back to land.