Sunlight spilled across the boundless sea, shimmering and sparkling. Occasionally, a few flying fish would leap out of the water, only to quickly dive back into the blue waves.
Propelled by the sea breeze, the Going Merry slowly moved forward, its white sails hoisted high, carrying Kai and his crew back onto the course towards the Grand Line.
Luffy lay on the bow, hands propped on the deck, his face full of anticipation:
"The Grand Line... We're finally almost there! I wonder what kind of adventures await us!"
"Don't get too excited too soon," Nami said, standing by the helm, her gaze fixed on the sea ahead.
"To enter the Grand Line, you first have to pass Reverse Mountain. That's not an easy feat."
"Reverse Mountain?" Usopp, sitting on the deck, shivered at the name.
His face instantly filled with tension, "That doesn't sound like a good place!"
"Hmph, scared already?" Zoro sat nearby, arms crossed, a hint of mockery at the corner of his mouth.
"I'm actually curious to see how dangerous this place really is."
Nami glanced at Zoro, her tone serious: "Dangerous? Of course it is. Don't any of you take it lightly.
The channel of Reverse Mountain isn't a place ordinary people can pass through."
"Nami, tell us more!" Luffy excitedly turned his head, his face full of curiosity, "What exactly is Reverse Mountain like?"
Nami secured the helm, then stood with her hands on her hips in the center of the deck, her tone serious:
"Listen up, Reverse Mountain is the entrance to the Grand Line, and also the convergence point of the Four Seas.
The waters of the East Blue, South Blue, West Blue, and North Blue all gather at Reverse Mountain, then climb to the summit through a countercurrent (reverse current) waterway, finally flowing into the Grand Line."
"Reverse current?" Usopp's expression grew even more nervous, "Water can flow uphill? How is that possible!"
"There are too many things in this world you can't imagine," Kai leaned against the ship's rail, looking calmly at Usopp.
"The upstream waterway is just the first test of entering the Grand Line."
Nami nodded and continued, "There are five waterways inside Reverse Mountain.
Four of them flow upstream from the Four Seas, converging at the summit.
The last one is the waterway that flows from the summit into the Grand Line.
What we need to do is follow the East Blue waterway upstream, and then rush down the waterway that flows into the Grand Line."
"That sounds so exciting!" Luffy's eyes lit up, almost jumping with excitement, "Going upstream and then rushing down, that's amazing!"
"Amazing my foot!" Nami glared fiercely at Luffy,
"It's not as simple as you imagine! The current at Reverse Mountain is extremely turbulent and terrifyingly fast. One wrong move, and the ship will be smashed to pieces!"
Zoro rubbed his chin, asking in a deep voice, "Besides the turbulent current, what other troubles are there?"
"Whirlpools and undercurrents." Nami's expression grew even more serious.
"The channel hides a large number of irregular whirlpools and undercurrents. These things can suddenly change the ship's direction.
If the steering isn't precise enough, the ship will deviate from the course and directly crash into the Red Line."
Sanji lit a cigarette and slowly exhaled a smoke ring: "Meaning, Miss Nami, our lives are entirely in your hands."
"You needed to say that?" Nami rolled her eyes at him. "Leave the ship handling to me; you guys just do what you're supposed to—like not getting in the way."
"Nami, don't worry!" Luffy raised his fist, his face full of confidence, "Just give me any difficulties! I'll use the power of the Gum-Gum Fruit to protect the Going Merry!"
Kai snorted coldly, his tone indifferent: "It'd be good if you just didn't drag us down."
"Kai!" Luffy glared at him, "You're getting more and more annoying!"
As they spoke, a colossal mountain range gradually appeared on the distant horizon.
It resembled a towering wall reaching into the clouds, with its mid-section enveloped by water, appearing like a natural marvel from afar.
"That's the Red Line and Reverse Mountain!" Nami pointed ahead, her voice tinged with nervousness, "We're here!"
"Wow!" Luffy's eyes widened, shouting excitedly, "It's so high! So big! Is this the entrance to the Grand Line?"
Usopp hugged the mast, trembling all over: "Can we really get through a place like this?"
"Don't be afraid, just charge through." Zoro gripped the sword at his waist, a hint of excitement in his eyes.
Kai looked at the mountain ahead, his gaze slightly narrowed: "Remember, everyone listen to Nami's command, don't move recklessly."
"Steady the course! Don't let the ship deviate from the channel!" Nami shouted, gripping the helm tightly, forcefully steering the Going Merry.
Suddenly, the water ahead began to spin violently, and a huge whirlpool appeared in the center of the channel.
"A whirlpool!" Usopp shrieked, clutching the mast, "Get out of the way!"
"Shut up! You're so annoying!" Nami gritted her teeth, quickly adjusting the direction.
She steered the Going Merry to skim past the edge of the whirlpool, narrowly avoiding being sucked in.
"That was close!" Luffy rubbed his head, letting out a sigh of relief, "We almost got pulled in!"
"There's more ahead!" Kai reminded coldly, his gaze fixed on the water, "Stay calm, don't make a fuss."
Indeed, another whirlpool appeared ahead, the water swirling wildly, creating waves.
Nami quickly adjusted the helm, but just then, an undercurrent suddenly appeared beneath the water, pushing the Going Merry's bow directly towards the center of the whirlpool.
"Oh no!" Usopp's face turned pale with fright, "We're going to be sucked in!"
"Don't worry! I'm here!" Luffy leaped up, stretching his arms to firmly grasp the mast, then yanked hard, forcefully pulling the bow back.
"Well done!" Kai glanced at Luffy, a hint of approval in his tone.
After a perilous journey, the Going Merry finally broke through the obstacles of whirlpools and undercurrents, arriving at the entrance of Reverse Mountain.
"Look over there!" Nami pointed ahead, a hint of excitement in her voice, "That's the waterway to the summit!"
Everyone followed her Guidelines (guidance) and saw a sight that made their eyes widen.
A narrow, long stream of water rushed directly from the sea level to the summit of Reverse Mountain, turbulent and violent, like an inverted waterfall surging towards the sky.
On both sides of the waterway were steep rock walls, covered with sharp stones, looking incredibly dangerous.
"It's breathtaking..." Zoro murmured, a hint of excitement in his eyes.
"This is the entrance to Reverse Mountain!" Luffy jumped up excitedly, "I'm going up! Grand Line, here I come!"
"Don't get too happy too soon." Nami's gaze was firm. "This part is the hardest; you'd better stay alert."
Nami took a deep breath, gripped the helm, and loudly declared: "Everyone get ready! Objective Reverse Mountain's summit!"
The Going Merry accelerated in the turbulent current, rushing straight towards the summit of Reverse Mountain, against the flow.
The ship's hull continuously ascended with the current, at a speed that made one's scalp tingle. The sea wind howled in their ears, and the entire ship was violently shaking.