The Underworld is the place where souls come to rest—so surely, it must have a way to preserve souls from fading away.
Thinking of this, Kaito immediately prepared to activate the power he had just obtained from the Revive-Revive Fruit.
But just then, Brook's voice echoed in Kaito's mind.
"Kaito-san, after losing the Revive-Revive Fruit, it seems I can no longer return to my body. Maybe... maybe it's best if I just move on."
"What?"
Kaito frowned. Didn't Brook used to long for the outside world? Why the sudden change of heart?
Brook spoke calmly.
"Now that I've left that skeleton, I feel… liberated. I've lived long enough. I want to go reunite with my crew. It's been such a long, long time..."
Hearing Brook's words, Kaito fell silent.
He began to wonder—was there still a need to bring Brook back to life? Did Brook truly want to die?
Sometimes, a long life isn't a blessing at all. Without someone dear to spend it with, it becomes a torment.
Not to mention, Brook had been living in a state that was neither human nor ghost.
But if he simply let Brook's soul return to the Underworld now, wouldn't that mean Brook died by his hand? Then what was the point of everything he had done up until now?
Besides, Brook still had bonds left in this world. There was still that whale, Laboon, who'd waited for him at Reverse Mountain for nearly fifty years!
Brook couldn't die yet—not like this, not by Kaito's hand.
With that thought, a faint blue frost began to rise from Kaito's left eye. This chill was fundamentally different from Aokiji's; it came from the Underworld itself.
"Brook, you still have an unfinished promise. So live on, and carry that promise with you."
The underworld's chill flowed into Kaito's hand, wrapping around Brook's soul.
Without powerful Haki or a special ability, anyone who touched that frost would be instantly frozen—possibly even have their soul injured.
But Kaito obviously wouldn't let that happen. The chill of the Underworld could harm souls, yes—but it could also nourish them.
Now that he possessed the Revive-Revive Fruit, and with the boost of the Rinnegan, he could freely shift that energy between its two states.
As Brook's soul was wrapped in that chill, he couldn't help but let out a few satisfied sighs.
But before he could even enjoy it, Kaito shoved him right back into his skeletal body.
Once the soul had returned, Brook's brow bone twitched slightly. He hesitated.
"I… I'm alive again?"
"Yeah. You're alive again."
Kaito confirmed it for him, then added a reminder,
"I've infused your soul with the chill of the Underworld. From now on, you can use its power. But remember—once it's used up, your soul will leave your body and return to the Underworld."
What Kaito had given Brook was a choice—to live or to die, to use that power or to let go.
Brook quickly understood what Kaito meant. His emotions grew complicated, and for a moment, he didn't know what to say.
Seeing Brook still frozen there, Kaito assumed he was still caught up in the life-or-death dilemma, so he said,
"Don't overthink it. If you still want to reunite with your crew, you can use up the underworld's chill now. Don't worry—it won't hurt."
Brook nodded slowly, feeling a deep sense of gratitude toward Kaito.
The Rumbar Pirates Brook once belonged to were more like adventurers. They did good wherever they went.
Just look at their motto:
"Even a crying child will smile again."
But pirate crews like that were rare. On his journey, Brook had seen what most pirates were like—taking whatever they saw by force. That was how most of them survived.
Brook himself never did such things, but he had grown numb to the sight.
He knew full well that if Kaito had wanted to take the Revive-Revive Fruit from him by force, he wouldn't have been able to stop it.
But Kaito didn't do that. He even went out of his way to Moria's place to retrieve Brook's shadow, and found a way to preserve Brook's life.
Brook felt like he actually owed Kaito now, which made him a bit embarrassed.
Kaito, of course, had no idea what Brook was thinking. If he did, he probably would've laughed out loud.
This Revive-Revive Fruit was incredibly powerful—Kaito felt like he was the one who got the better deal. Why would he ever think Brook owed him anything?
But then again, this was the pirate world. Some of those unspoken rules were deeply rooted.
Kaito realized it wouldn't be right to leave Brook alone here. It would be better to let him go see Laboon—to spare the whale from endlessly smashing its head against the Red Line in sorrow.
With that, Kaito had an idea. He said to Brook,
"Do you still remember Laboon?"
"Laboon!?"
Brook was shocked to hear that name come from Kaito's mouth.
He couldn't even remember how many years it had been since he'd last heard it. How could he ever forget Laboon?
Even though Laboon was a whale, Brook had long considered him a true crewmate—someone he'd entrust his life to.
Brook forgot all manners in that moment. Gripping Kaito by the shoulders, he shouted,
"Kaito-san, how do you know Laboon? You've seen him, haven't you? Where is he now? Is he okay?"
The questions tumbled from Brook's mouth, revealing just how desperate he truly was.
Kaito understood his reaction. After all, the story of Laboon was one of the more emotional early arcs in One Piece, and it had moved him deeply too.
All things have souls—and sometimes, the feelings between people pale in comparison to the bond between a person and a whale.
Kaito had already fulfilled many dreams in the One Piece world. So why not grant one more—for these two "fools"?
He stared into Brook's empty eye sockets and said,
"He's still waiting for you in the same place. He's never left. Not for a single moment. Do you want to go see him?"
"I…"
Brook almost blurted out "Of course," but then he remembered the promise he made to Laboon.
It wasn't just about meeting again. The reunion was supposed to happen after the Rumbar Pirates had circled the world.
But after leaving Laboon, the crew had fallen victim to a plague. In the end, only Brook had survived, thanks to the Revive-Revive Fruit—watching over an empty ship for nearly fifty years.
Brook desperately wanted to go see Laboon. He'd thought about it to the point of madness.
But their promise wasn't fulfilled. And to Brook, a promise was a man's word—something that could never be broken.
Now he found himself caught in a painful dilemma—torn between keeping his promise, and reuniting with his friend.