The Grand Line was a sea of miracles.
One of those miracles was the Knock-Up Stream, a massive, violent current that could shoot ships thousands of meters into the sky.
But what Kaito's crew found wasn't the Knock-Up Stream everyone knew.
It was its sister.
A rarer, calmer, but equally mysterious phenomenon.
A Sky Current that carried ships along a spiraling water path straight into the clouds.
And unlike the violent Knock-Up Stream, this one required not just courage—but precision.
The Queen's Grace approached the swirling vortex of water that stretched upward like a towering, twisting ribbon.
The sky shimmered where the current pierced the clouds.
It was a path rarely traveled.
Nojiko gripped the helm tightly, her knuckles white.
"According to the Sky Map we got from the remnants of Skypiea, this is the passage Enel sealed off long ago."
Aisa leaned over the railing, wide-eyed. "It's like a staircase made of water…"
Kaito stood at the bow, the wind tugging at his coat. "Let's take it."
Kuina stepped beside him, a faint spark trailing from her fingertips. "It won't be as violent as the Knock-Up Stream, but it won't be safe either."
Khalifa adjusted her glasses, already calculating the possible gravitational pull and water speeds. "We'll need precise coordination to stay balanced or we'll be thrown off mid-ascent."
Carmen smirked, her arms crossed. "Sounds like fun."
Conis tightened her grip on her harp, her nerves rattling. "Will we… see other sky islands?"
"Possibly," Kaito replied. "But our destination isn't Skypiea this time. It's the ancient Sky Ruins—untouched by even the Shandians."
Nojiko called out. "All sails ready! Once we enter the current, we won't be able to stop until we reach the top!"
The Queen's Grace creaked as it was pulled toward the spiraling stream.
Kaito's heart pounded—not with fear, but with anticipation.
This was what it meant to sail.
To find impossible seas.
To chase rivalries.
To carve a path where maps didn't exist.
Into the Spiral: A Test of Seamanship
As the ship entered the stream, the world tilted.
The water beneath them surged with terrifying force, yet remained perfectly smooth within the spiraling path.
Nojiko's hands moved quickly on the helm. "Adjust the rudder! Brace for shift—three degrees starboard!"
The ship shuddered, but held steady.
Aisa's eyes darted, using her Observation Haki to sense the flow of the current. "There's a crosswind coming in the next turn!"
Carmen rushed to adjust the sails. "Got it!"
Conis stabilized the ropes, helping Khalifa secure the main mast.
Kuina stood firm, watching the walls of water race beside them, thunder occasionally crackling from her fingertips—not in battle, but in excitement.
They were ascending fast.
Above them, the clouds parted, revealing a shimmering gateway that looked like a ceiling of light.
"This is it!" Nojiko shouted. "Once we pass through, we'll be in uncharted skies!"
Kaito smiled. "Let's go."
The Queen's Grace surged upward, riding the final twist of the spiral, piercing through the sky like a bullet.
For a moment, gravity vanished.
The crew felt weightless as the ship broke through the light.
And then, the Queen's Grace landed smoothly on a soft, floating sea—a thin layer of cloud water that stretched endlessly across the sky.
The silence that followed was breathtaking.
They had reached the Ancient Sky Ruins Sea.
Above the Skies: A New Frontier
Before them lay fragments of ancient islands, some floating in pieces, others tethered by giant vines to central, intact sky platforms.
Unlike Skypiea, this place was untouched—overgrown, wild, and eerily quiet.
Tall stone pillars jutted from the clouds, covered in moss and vines.
Massive statues, broken and half-buried, lined the cloud sea like forgotten sentinels.
Nojiko anchored the ship near one of the larger platforms. "This place… it's not on any map."
Khalifa examined the carvings on a nearby pillar. "The language is older than anything in Skypiea."
Kuina's gaze drifted toward the distant ruins. "There's something here. Something waiting."
Aisa focused her Haki. "I feel… movement. Guardians maybe."
Kaito grinned. "Let's find out."
First Exploration: Splitting into Teams
They split into two groups.
Team 1 – Kaito, Kuina, Nojiko: Investigate the main temple in the center of the ruins.
Team 2 – Carmen, Khalifa, Aisa, Conis: Explore the surrounding platforms and search for supplies and safe paths.
Kaito's team crossed a bridge made of cloudstone, the material firm underfoot despite its appearance.
The carvings along the bridge depicted battles between sky warriors and unknown beasts, with strange symbols representing a power source at the heart of the ruins.
Nojiko ran her hand over the stone. "These symbols… they don't match Skypiea's history."
Kuina's grip tightened on her swords. "What are they hiding here?"
As they reached the temple's entrance, they encountered massive doors covered in vines, sealed with an intricate lock that pulsed faintly with sky energy.
Kuina stepped forward, her thunder sparking against the lock's ancient metal.
When her lightning touched it, the lock glowed—reacting to her presence.
The doors rumbled and slowly creaked open.
Inside, a soft, golden light beckoned.
Meanwhile: Carmen's Team – Sky Beasts and Sky Fruits
Carmen's team explored the smaller platforms, occasionally encountering small sky beasts—flying fish with glowing fins, cloud serpents that flickered in and out of visibility.
Aisa deftly used her Haki to dodge surprise attacks, landing precise slingshot shots to drive them away.
Khalifa engaged one of the more aggressive cloud serpents, using her swift movements and hand-to-hand strikes to protect Conis.
"I didn't expect the sky to be this lively," Khalifa commented as she dispatched another serpent.
Carmen chuckled. "That's what makes it fun."
Conis, though nervous, found a strange plant with small, pulsing fruits along the edge of a broken sky pillar.
They glowed faintly with electric patterns.
"Khalifa, Carmen—look," she called.
Carmen examined it closely. "I've seen something like this in the sky archives."
Aisa's eyes widened. "Is it a Devil Fruit?"
"No," Carmen said. "It's… something else. A Sky Fruit. They're rare, non-Devil power sources—energy-enhancing fruits used by ancient sky warriors."
Khalifa picked one carefully. "We'll bring it back. Maybe Kuina can use it."
Inside the Temple: The Awakening
Inside the temple, Kaito's team found a central altar bathed in sky light.
At its center rested a Thunder Fruit.
Not just any Thunder Fruit—a refined form, purer than the one once held by Enel.
The markings on the altar showed that it was guarded, waiting for a worthy wielder.
Nojiko read the inscriptions aloud. "Only those who have tamed the sky's rage may inherit its core."
Kaito turned to Kuina. "This is your trial."
Kuina stepped forward without hesitation.
The moment her hand touched the altar, the temple shook.
A figure of condensed lightning formed—an ancient guardian, shaped like a humanoid sky warrior, crackling with raw electric power.
Kuina drew her blades.
The trial had begun.
The Lightning Duel
The guardian moved like lightning itself.
Each step left arcs of static behind.
Kuina's thunder flickered in response, her control still rough compared to this ancient entity.
The battle was fierce.
Each clash sent waves of electricity through the temple walls.
But Kuina adapted.
She remembered her fights in Skypiea.
She remembered her duel with Zoro.
She remembered her promise to Kaito.
And she forged her own rhythm, syncing her blade strikes with controlled bursts of thunder.
When the guardian unleashed a final, concentrated blast, Kuina met it head-on, channeling everything into a precise cross-slash infused with her own thunder.
The clash illuminated the entire temple in blinding light.
When it faded, Kuina remained standing.
The guardian dissipated, its duty fulfilled.
The Thunder Fruit on the altar pulsed softly, as if acknowledging her.
She picked it up, studying it quietly.
"This is mine now," she whispered.
Back at the Ship: The Crew Reunites
When Carmen's team returned, they presented the Sky Fruits they had collected.
Kuina returned with the Thunder Fruit, her victory written across her calm face.
"It's done," she said simply.
Aisa blinked. "You already finished your trial?"
Kuina nodded. "There's no going back now."
Kaito smiled. "Good. Because this era won't wait for us."
The crew settled down for the night, the sky above them painted with unfamiliar stars.
Tomorrow, Kuina would eat the Thunder Fruit.
Tomorrow, their next journey would begin.
The Grand Line was vast.
And their story had only just started.