Grand Line

At the private deepwater dock of the Tuna Shipyard, an extremely bizarre single-masted medium-sized sailboat was moored.

Its hull was a deep dark red, made from top-grade hardwood the shipyard owner had paid a hefty sum to acquire on the black market, mixed with scraps of Treasure Tree Adam. Its figurehead had been carved into a sharply faceted meteorite, giving off a cold, forbidding aura that kept strangers away.

However, what puzzled the dockworkers most was the ship's draft.

"L-Lord Grayrock," the shipyard owner said, wiping waterfall-like cold sweat from his forehead as he watched workers continuously carry cargo into the hold. His voice trembled. "Are you sure you want to load this much stone? This is already the fiftieth ton! No matter how sturdy this ship's keel is, loading so much high-density granite and basalt means that if it encounters even slightly rough seas, it could sink straight to the bottom!"

Below deck, the massive lower hold that should have been used to store food, fresh water, and treasure was densely packed with premium rocks carefully selected by Rain. From heavy, hard black basalt to sharp High-Pressure Obsidian ore, there were even several tons of iron-rich hematite.

Rain stood on the deck in a brand-new black trench coat, letting the salty sea breeze whip through his black hair.

"You just take the money. Whether the ship sinks is my concern." Rain casually tossed the final payment of five million Beli into the owner's arms, then kicked away the gangplank connecting the ship to the dock.

Of course, he knew the danger of overloading a ship. But for a Logia user preparing to brave the Grand Line alone, the deadliest weakness on the vast ocean was a lack of elements.

If he encountered a powerful enemy or extreme weather at sea, with nothing but seawater around him, he, a Rock-Rock Fruit user, would become like water without a source. These fifty tons of rock in the hold were his ammunition depot, his spare armor, and the true "heart" of his ship.

"Raise anchor."

Rain gave a low command. Rather than pulling the ropes for the sails, he walked straight to the stern.

At his request, the shipyard owner had left a massive semi-open cavity below the stern, directly connected to the sea.

Rain slowly crouched down and pressed both hands against the deck.

At a thought from him, the several tons of basalt in the lower hold seemed to come alive instantly. Like living liquid, they surged rapidly through the gaps in the planks toward the cavity at the stern.

Under Rain's incredibly precise control, the rocks rapidly reassembled and interlocked the instant they touched seawater, forming a massive, complex multi-bladed rock propeller.

Then, Rain slightly tensed his calf muscles, continuously channeling his kinetic energy and the Devil Fruit's assimilation power into the stern.

"Vrrrrm—!"

The propeller made from dense rock beneath the water began spinning wildly at a terrifying speed that defied all reason! Enormous spray exploded from the stern, and the powerful reverse thrust was like strapping a heavy torpedo to the ship's rear.

"Boom!"

Under the ghost-struck gazes of the shipyard owner and all the workers, the sailboat, loaded with fifty tons of stone and without even lowering its sails, actually tore across the sea, dragging a long white wake as it shot toward the horizon!

"Th-That's how Devil Fruit users sail? He's a complete monster!" The owner collapsed onto the dock, muttering to himself.

The sky was dark, and gale-force winds howled. Heavy lead-gray clouds seemed poised to crush the sea, while suffocating moisture and deafening roars filled the air.

Rain stood at the bow and looked up.

Ahead of him stood a dark red continental cliff stretching from heaven to earth, its summit utterly invisible. At the center of that continent, the waters of the Four Blues converged in a frenzy, forming a terrifying canal that flowed upward against the current and shot into the sky.

This was Reverse Mountain, the legendary sole entrance to the Pirate Graveyard—the Grand Line.

"I finally made it."

Rain took a deep breath as the gale whipped his trench coat with a loud flutter. Even for someone as calm as him, facing nature's greatest spectacle made his heartbeat quicken slightly.

"The current is too fast. If an ordinary wooden hull hits either side of the Red Line, it'll be smashed to pieces in an instant."

Rain did not let his guard down in the slightest. He suddenly brought his hands together, and over ten tons of granite in the lower hold responded at once. Like gray mercury, the rocks swiftly coated everything below the ship's waterline, as well as its bow.

In just a few seconds, the wooden sailboat had become an armored icebreaker clad in a thick shell of rock.

"Charge in!"

Rain increased the output of the Rock Turbine at the stern. The sailboat let out a deep roar and plunged headfirst into that frenzied canal flowing upstream!

"Rumble, rumble, rumble!"

The moment it entered the canal, an intense sensation of weightlessness and violent tearing struck at once. White, raging spray surrounded them, and the deafening roar of water drowned out every other sound. The ship bucked violently in the rapids, nearly crashing into the blade-like red cliffs on both sides several times.

"Bang! Crack!"

With a massive crash, the ship's left side scraped hard against a protruding reef. If it had been an ordinary wooden vessel, its entire port side would have been torn apart. But the rock armor Rain had applied beforehand withstood the impact, leaving only a long string of blinding sparks across the Red Line's cliff face.

"Hold steady!"

Rain fused both legs completely with the deck. Like the ship's brain, he continuously adjusted the stern turbine's angle and speed through his Devil Fruit power, performing extreme precision maneuvers on this death waterslide leading into the clouds.

Who knew how long passed? Perhaps minutes, perhaps hours.

The mist around them suddenly turned bitterly cold, while the howl of the wind gradually died down.

"We broke through!"

The sailboat suddenly burst out of the thick clouds, and blinding sunlight instantly flooded the deck.

Rain stood at the bow, gulping down the thin, frigid air at high altitude. Beneath his feet lay an unfathomable sea of clouds. Ahead, the canal's waters crossed the summit of the Red Line and began pouring madly down the other side.

That was the Grand Line!

A brief sensation of weightlessness struck. The sailboat crossed the peak and, like a roller coaster, began plunging vertically down the steeper, more violent descending canal toward the unknown sea below!

"Now!"

A sharp gleam flashed in Rain's eyes.

Charging down from tens of thousands of meters in the air along the raging current, with gravitational acceleration compounded by the force of the water, the ship could very well break apart the instant it hit the Grand Line's sea surface, unable to withstand the terrifying impact. Countless pirate crews had crossed the peak only to die on this final descent.

But he was a Rock-Rock Fruit user.

"Release all the rocks in the lower hold!"

Rain thrust both hands upward.

"Boom!"

The deck at the bottom of the cabin instantly opened. Under Rain's call, the remaining thirty-plus tons of basalt and granite erupted skyward like a volcanic explosion, hovering above the sailboat.

"Minimize density! Extend!"

Rain gritted his teeth, veins bulging on his forehead. This was an advanced application of his Devil Fruit that he had practiced day and night after being inspired by Capone Bege.

Tens of thousands of rocks in midair let out a teeth-grinding scrape under Rain's extreme compression and reconstruction. They were frantically flattened and crushed, then linked and nested together through his Devil Fruit power like woven fibers.

In just a few seconds, thirty tons of heavy rock transformed above the sailboat into a massive rock wing, thin as cicada wings yet incomparably tough!

It was like a super parachute pieced together from countless fine stone scales, firmly suspending the sailboat in midair.

"Whoom—!"

The violent wind instantly filled the massive rock wing. The sailboat, which had been plummeting madly under gravity, abruptly jerked to a halt under the terrifying air resistance, its descent slowed by a full seventy percent!

"It worked!"

Feeling the immense pulling force from above, Rain finally curled his lips into an exceptionally wild grin.

Heavy stone could not fly, but as long as it was flattened to the extreme and turned into scale-like wings that followed the airflow, rock could conquer the sky as well!

Like a gray storm cloud, the massive rock wing carried the sailboat in a steady glide through the gale and rushing current. Through the clouds, Rain could already clearly see the deep-blue sea below, along with the iconic Twin Cape lighthouse at the end of the canal.

"So this is the Grand Line..."

Rain stared at that sea, which concealed countless monsters, treasures, and unknowns. There was no fear in his eyes—only the excitement and fervor of a hunter who had discovered a premier hunting ground.

"Splash—!"

Several minutes later, slowed perfectly by the rock wing, the sailboat glided smoothly onto the waters of Twin Cape like a light leaf, splashing up a modest spray of white water.

With a flick of Rain's wrist, the massive rock wing above instantly disintegrated, returning to heavy chunks of stone that fell precisely back into the bottom of the hold with dull impacts.

The sea breeze swept past, carrying the Grand Line's uniquely unpredictable air.

Rain straightened his black trench coat and walked to the bow.

Grayrock, the bounty hunter from the West Blue, had officially set foot in this sea of monsters.