The Going Merry successfully crossed the peak of Reverse Mountain and plunged down the roaring descent.
The violent impact and sudden drop left Cain feeling deeply unsettled.
It wasn't the weightlessness of the fall that bothered him, but rather a strange, hollow feeling in his chest—like he had forgotten something incredibly important.
"BWOOOOOOOOH—!"
A deafening, mournful roar echoed across the sea, instantly drawing the crew's attention.
Cain's heart jolted. He remembered the sound at once.
It was Laboon.
On deck, Sanji realized something was horribly wrong and immediately called out.
"Nami-san! There's a mountain ahead!"
"A mountain? That can't be right! After passing Twin Cape, there should be nothing but open sea!" Nami rushed to the bow, doubting her own navigational charts.
But as the ship drew closer and the swirling mist began to clear, the enormous black mass obstructing the horizon finally came into view.
She gasped in absolute shock. "THAT'S NOT A MOUNTAIN! IT'S A WHALE!"
Seeing the Going Merry hurtling straight toward the colossal beast, Luffy bolted to the bow and frantically prepared the main cannon, intending to fire a blast to force the ship to slow down.
But before Luffy could light the fuse, the Going Merry smoothly decelerated on its own.
Instead of violently crashing into the whale, the ship came to a steady halt just above the churning rapids.
Cain had acted. He conjured thick clusters of flame clouds to catch the Going Merry, suspending the entire ship steadily in midair.
"Strange.... The Merry didn't snap her figurehead or smash her railings like she did in the original timeline, the ship is perfectly intact. So why do I still feel so uneasy?" Cain muttered to himself.
A sudden throbbing pain flared behind his eyes.
Had he really forgotten a crucial plot point, or had his Observation Haki just triggered on a hidden danger? That ominous dread was only growing stronger, and his control over the flame clouds wavered slightly.
"What is Cain muttering about... wait, Cain! Put us down!" Nami intended to scold him, but as she took a step, she realized the Merry was slowly rising into the air, drifting closer and closer to the crown of the giant whale's head.
"It hurts... So painful..."
Abrupt, muttered cries of pure agony slipped into Cain's ears.
He whipped his head around and looked at the navigator. "Nami, are you hurt?!"
"N-No! Just hurry up and put the ship down!" Nami's voice trembled, her legs shaking with absolute terror.
Just below them, the island-sized whale was slowly opening its enormous mouth. Its pitch-black throat looked like an abyss capable of swallowing the sky itself.
Cain looked at his crewmates.
Zoro and Sanji seemed perfectly fine. Usopp was curled into a ball, trembling. Luffy stood by the cannon, grinning excitedly at the massive monster.
"Luffy, do you hear anything?" Cain asked.
"Hmm... maybe? Or maybe not? I don't know." Luffy scratched his head, frowning slightly.
The moment Luffy spoke, Cain's headache spiked into blinding agony.
He looked down at Laboon thrashing below and was violently jolted awake by the realization.
In the next second, Cain deliberately tilted his head and put on a weak, exhausted expression.
"Ah... I'm out of strength."
The flame clouds vanished into thin air.
The Going Merry dropped like a stone, plunging straight down into the gaping maw of the island whale.
"WHAT THE HELL ARE YOU DOING?!" Zoro and Sanji roared as they plummeted into the dark.
"AHHH! WE'RE GOING TO GET EATEN!" Nami screamed in pure panic.
Usopp had already fainted from fright. Only Luffy clung tightly to the figurehead, shouting with unbridled excitement about the adventure.
Cain gently rubbed his temples as the darkness swallowed them.
He finally figured it all out.
...
In his previous life, he retained many memories of the One Piece manga, but a great number of the finer details were buried deep in his subconscious.
Earlier, while steering the ship through the raging rapids of Reverse Mountain, Cain pushed his Observation Haki to a level of focus he had never reached before.
If he made even the slightest mistake handling the helm, the Merry would be reduced to splinters and his crew would drown.
He couldn't afford a single moment of carelessness.
Garp had scolded him relentlessly for not honing his Observation Haki properly. This was the very first time Cain actively and wholeheartedly pushed the ability to its absolute limit.
That active effort was completely different from the passive concentration he used during sparring matches.
It was precisely that extreme focus resonating with his subconscious knowledge of the lore that caused the inexplicable agitation.
His Observation Haki was warning him that the timeline was changing.
It was like a wife's teacup suddenly shattering the exact moment her husband meets disaster—an omen impossible to put into words.
This unusual resonance not only warned him of danger but unexpectedly awakened the Voice of All Things, allowing Cain to hear Laboon's cries of agony and instantly remember Vivi and Mr. 9.
That was the missing piece.
Earlier in the Calm Belt, Cain wasted too much time showing off his Conqueror's Haki and explaining the power system to the crew.
Because of that delay, Vivi and her Baroque Works partner managed to infiltrate Laboon's stomach and corner Crocus before the Straw Hats arrived.
Vivi's group was actively trying to kill Laboon from the inside, intending to take the mountain of whale meat back to Whiskey Peak to feed their bounty-hunting town.
Even though Cain knew Vivi was secretly an undercover princess, no one could guarantee what desperate actions she and Mr. 9 might take to secure the kill.
If anything permanent happened to Laboon, the future reunion with Brook would be ruined forever.
Because his subconscious lore memories resonated with his Observation Haki, he pinpointed the problem before it was too late.
His Haki was warning him to save Crocus and Laboon!
...
Laboon's huge mouth snapped shut.
Cain immediately conjured flame clouds again, catching the Going Merry before it smashed into the churning water inside the whale's stomach.
Or rather, the lake of gastric acid.
Unexpectedly, the interior of Laboon's body was not pitch-black at all. Instead, the massive cavern was painted with a vibrant blue sky and white clouds.
"We are really inside a whale's stomach...?" Nami stared in sheer astonishment at the fake sky.
Zoro and Sanji had already clenched their fists, marching over to teach Cain a lesson about dropping ships into monsters!
But before they could throw a punch, Cain unleashed a concentrated burst of Conqueror's Haki, freezing them in their tracks.
He stepped on the air using Geppo and launched himself toward the small island house in the distance.
"What happened?" Luffy asked curiously.
"No idea. But there are definitely enemies here, and they're not weak," Zoro said, his hand dropping to his sword.
For Cain to unleash his aura before even making visual contact, the opponent had to be formidable.
Everyone looked up and saw wisps of black smoke drifting near the painted sky. The acrid smell of gunpowder lingered heavily in the air.
A battle had just taken place here.
By the time Luffy and the others rowed the ship over, all they found were an unconscious man and woman tied up on the ground, along with an old man covered in black soot from a cannon blast.
Nami hurried over to check the old man's injuries while Luffy enthusiastically circled him, firing off endless questions.
Usopp remained safely unconscious on the ship.
Seeing the treasured straw hat resting on Luffy's head, and feeling grateful that these pirates had saved Laboon, the old man introduced himself.
"My name is Crocus. I'm the caretaker of the Twin Cape lighthouse. I am seventy-one years old, blood type AB. As for these two, they're thugs from a nearby island. They've been trying to kill Laboon for a long time. After all, a whale this size has enough meat to feed their entire town for years."
"Laboon? You mean this giant whale?" Luffy asked.
Crocus nodded, then slowly began recounting the tragic tale of Laboon and the Rumbar Pirates.
Cain already knew the whole heartbreaking story, so he stayed off to the side, silently keeping watch over Vivi and Mr. 9.
He used his Observation Haki to monitor the whale's vitals while lying on his back, wearing his new over-ear headphones.
They played no sound, but he hummed a quiet tune to himself in an attempt to calm his racing mind.
This strange warning from his Haki had fully awakened him to a terrifying reality.
His mere presence was altering the timeline, creating irreversible butterfly effects.
If he wanted the Straw Hat Pirates to keep sailing smoothly and growing stronger on their own, he needed to leave the crew for a while.
It was the only way to ensure they wouldn't miss their fated meeting with Ace in Alabasta, and that their path wouldn't be thrown completely off course by relying on his overwhelming strength.
Aside from that, there was Uta.
Cain silently estimated the timeline.
Uta's mental state was likely deteriorating rapidly by now, but she might still listen to reason.
Her plan might not have fully taken shape yet. In the original timeline, this was the exact year Uta was rising to global fame as a diva.
Leaving the crew now was the best time to intervene and save her.
If he stayed with the Straw Hats, not only would he risk preventing their reunion with Ace, but he would completely miss the narrow window to change Uta's tragic fate.
Furthermore, he needed to be present for the major upcoming events: encountering Blackbeard in Jaya, the clash at Enies Lobby, and the inevitable showdown to stop Ace's capture to prevent the Marineford War entirely.
On top of everything else, Cain still had his own desperate plans involving Kaido and Wano Country.
He simply couldn't afford to drag his feet in the Paradise half of the Grand Line.
Ace on one side. Uta on the other. And a storyline that was already veering dangerously off course.
Cain felt his frustration mounting.
He pulled off the silent headphones, walked over to Crocus, and asked softly.
"Crocus-san... do you happen to have an Eternal Pose for the Kingdom of Elegia?"
---------
Since the strawhats still in the Grandline, Cain will separates himself from the strawhats from time to time, only there when the crew is enterin a major arc... Next arc Cain will go to elegia and there will be some flashback for a few chapter.