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The first thing Law heard was an explosion.
The second thing he heard was screaming.
The third thing he heard was his own voice, already exhausted before he had even opened his eyes.
“...Luffy, I’m going to kill you,” Law muttered.
A warm arm tightened around his waist.
“No, you’re not,” Luffy mumbled sleepily.
Law stared at the ceiling of the room.
Their room.
It had once been quiet.
It had once been a place where Law could sleep for more than four hours without waking up because something was either on fire, broken, or screaming.
He closed his eyes and immediately another explosion rocked the ship. A piece of wood somewhere above them cracked.
Law sat up immediately.
“Absolutely not,” Law said.
Luffy blinked away, his hair sticking up in every direction. His sleepy scent enveloped Law, bringing his already annoyed mood down from dangerous levels.
“Is breakfast ready?” Luffy asked.
Law turned slowly. “Why is that your first thought?”
“Because something exploded,” Luffy said.
“That’s not a normal connection to make,” Law said.
Luffy shrugged. “It usually means food.”
“It usually means our daughter is up to something,” Law huffed.
Luffy’s face immediately lit up. “Our daughter!” he exclaimed.
Law regretted everything.
He had spent years surviving other pirates, marines, warlords, and enemies who wanted him dead.
None of those things had prepared him for parenting Monkey D. Luffy’s child.
Or rather, parenting their child.
Because somehow, despite all logic, the two of them had created someone who was somehow the perfect combination of them both. And that was terrifying.
Law pulled on his coat and walked out onto the deck, already knowing what he was going to find.
He was not disappointed.
Or rather, he was exactly as disappointed as he expected to be.
In the middle of the deck stood Rosi. She was thirteen years old, her dark hair messy from the wind, a confident grin on her face, and holding a wrench almost larger than her entire arm.
Next to her was Ace. He was nine years old, wearing a pair of goggles much too big for his face, looking like he had just accomplished the greatest achievement of his life. He was currently hanging precariously on a rope tied to the mast.
“Look, Daddy!” Ace shouted happily. “We made something!”
Law stopped. Slowly, very slowly, he looked at the machine they were standing next to, then at Rosi, then at Ace, then back at the machine.
“...No,” Law said.
Rosi crossed her arms.
“You haven’t even seen what it does,” she said.
“I’ve seen enough,” Law said.
Rosi frowned. “You don’t even know what it is.”
“I know it was built using Franky-ya’s tools, three pieces of Sunny’s spare parts, and something that is definitely from Usopp-ya’s workshop,” Law said.
Rosi looked away, looking sheepish. “...Maybe,” she admitted.
Law’s eyes twitched. “Rosi…”
“I borrowed them,” Rosi said.
“Borrowing implies you asked, and that everyone is going to be getting their things back.”
“I was going to ask,” Rosi murmured.
“When?” Law asked.
“When it worked,” Rosi said.
Law stared at her, and she stared back, defiant. That was the problem, because the look was not Luffy’s. Not completely.
It was his. It was his stubbornness, his confidence, his absolute belief that if he just tried hard enough, everything would work out.
Except she had Luffy’s complete disregard for danger mixed with Law’s tendency to think he was smarter than everyone else.
It was a horrible, dangerous combination. It was also very familiar.
“Why,” Law asked slowly, “is my daughter holding a wrench bigger than her arm?”
Rosi looked down at it. “Oh, this thing?”
She shrugged. “It was too heavy for Ace to hold it.”
Law sighed quietly.
Ace raised his hand proudly. “I helped!” he announced.
Law looked at him. “You did?”
Ace nodded enthusiastically. “I was the assistant.”
“Why?” Law asked.
“Because Rosi said I could,” Ace said.
Law closed his eyes.
Of course his nine-year-old had been recruited. Ace looked so proud that Law couldn’t even be angry. That was the worst part.
Ace adored his sister completely. Where Rosi went, Ace followed. If Rosi climbed something, Ace climbed after her. If Rosi had an idea, Ace believed it was the greatest idea anyone had ever had.
Rosi could announce she was going to jump off the Sunny because she had discovered she could fly, and Ace would probably say, “Wow! Rosi’s going to fly!” before asking if he could come too.
“Hi, Papa!” Ace called.
Law looked up. Ace was, in fact, sitting on top of the mast. Law felt his soul leave his body.
“Rosi,” Law said.
“Yeah?” Rosi asked.
“Why is he up there?” Law asked.
“He wanted a better view,” Rosi said.
“He’s nine,” Law said.
Rosi shrugged. “He’s adventurous.”
“He’s nine,” Law repeated.
Rosi frowned, as if she couldn’t see his point. “He’s a pirate.”
Before Law could say anything else, a familiar laugh echoed across the deck.
“Shishishi!” Luffy laughed.
Luffy came running out, completely awake now. He looked at the machine, at Rosi and Ace, and his face lit up.
“That’s amazing!” Luffy exclaimed.
Law immediately pointed at him. “No,” he said.
Luffy blinked. “What?”
“No,” Law repeated.
“But look at it!” Luffy said.
“I know what you’re thinking,” Law said.
“It’s cool!” Luffy protested.
“You think everything is cool,” Law said.
“Because everything is!” Luffy said.
“That is not a defense,” Law said.
Luffy walked closer and inspected the machine.
“What does it do?” Luffy asked.
Rosi’s grin returned. “It’s going to make sailing easier.”
Luffy gasped. “That’s awesome!”
“Thank you!” Rosi said.
“You made something to help the Sunny?” Luffy asked.
“Yeah!” Rosi said.
“Like a real pirate!” Luffy exclaimed.
Rosi looked incredibly proud. Law looked horrified.
“Why are you encouraging this?” Law asked.
Luffy turned.
“Because she’s being amazing,” he said.
“She is creating unknown machinery using stolen tools,” Law said.
“Borrowed,” Rosi corrected.
“Stolen,” Law said.
“Borrowed,” Rosi insisted.
“Rosi,” Law said, raising a brow at her.
“...Borrowed temporarily,” Rosi mumbled.
Luffy laughed. “She’s just like us!”
Law went quiet.
She was. And that wasn’t so scary anymore.
________________________
The rest of the crew gathered after hearing the commotion.
Considering the Sunny’s history, that was not unusual.
Nami walked onto the deck, took one look at the machine, and immediately sighed.
“No,” Nami said.
Law looked at her. “Thank you,” he said.
“She built another thing?” Nami asked.
“Yes,” Law said.
“With Franky’s tools?” Nami asked.
Law sighed quietly. “Yes.”
Nami rubbed her forehead. “I knew this would happen.”
Luffy pointed. “Look! They’re becoming great pirates!”
Nami stared at him.
“We are raising disasters,” Nami said.
“Great pirates,” Luffy said.
Nami sighed quietly. “Disasters, Luffy.”
“Great pirates,” Luffy repeated.
“Luffy,” Nami said.
“Great disasters?” Luffy said.
Nami paused. “...That’s unfortunately accurate,” she admitted.
Sanji came running over moments later.
“My little angels!” the cook exclaimed.
Law knew immediately where this was going.
Sanji crouched beside Ace.
“Are you hungry, little man?” Sanji asked.
Ace’s eyes widened. “Really?”
“Of course!” Sanji said.
“Can I have something sweet?” Ace asked.
“Anything,” Sanji said.
Law turned.
“Sanji-ya,” Law said.
“What?” Sanji asked.
“You cannot award him for being involved,” Law said.
“He’s adorable,” Sanji protested.
“He was hanging from the mast,” Law said.
Sanji shook his head. “He was brave.”
“He’s nine,” Law sighed.
“He’s a very brave nine-year-old,” Sanji muttered indignantly.
Rosi laughed and Ace smiled sweetly. Law hated that he couldn’t stay annoyed, not when they looked so happy.
Robin watched from nearby, a small smile on her face.
“You know,” Robin said, “Rosi reminds me of you.”
Law looked at her. “That is exactly what worries me.”
“She’s curious,” Robin said.
Law shook his head. “She’s reckless.”
Robin smiled softly. “She’s determined, that’s for sure.”
Law couldn’t argue with that, but he said anyway, “She’s stubborn.”
Robin smiled. “Yes,” she said.
Law sighed. “She’s both of us.”
Robin looked over at Rosi, who was now explaining the machine to Luffy while Ace proudly added details that made no sense.
“She’s also very loved,” Robin said.
Law went quiet, because that was true more than anything else. She was loved. Ace too.
They had built something neither of them thought they would ever have.
A family. A loud, impossible, chaotic family.
A family that exploded things before breakfast. A family that made him tired every single day.
A family he would never trade.
_________________________
Later that evening, after the machine had been dismantled and Franky had assured everyone that nothing important had been damaged, Law sat on the deck.
Rosi was nearby, reading through one of his old books. Ace was asleep against her side.
Even asleep, his hand was still holding onto her sleeve, as if he was afraid she would disappear.
Law watched them quietly. They were two kids who had become the center of his entire world.
Rosi looked up.
“What?” she asked.
Law blinked. “Nothing.”
“You’re staring,” Rosi said.
“I’m thinking,” Law said.
“About what?” Rosi asked.
Law hesitated, because lately, he had noticed something. Rosi wasn’t just getting older, she was starting to wonder about the world, about pirates, about where she came from, about the people who had shaped her life, and about the things Law and Luffy had never told her.
Questions were coming. He knew that. Soon, she would start asking, and he didn’t know if he was ready for that.
But looking at her now, looking at the girl who was somehow half his stubbornness and half Luffy’s impossible dreams, he knew one thing.
No matter what questions she asked, no matter what answers she found, she would always be their daughter, and Ace would always be her little brother.
Even if raising them was going to be the death of him.
Especially if Luffy kept encouraging their bad behavior.
From somewhere across the deck, Luffy shouted, “TORAO! ROSI MADE ANOTHER THING!”
Law closed his eyes.
“Of course she did,” Law muttered.
Ace immediately woke up.
“Rosi made something?” Ace asked.
Rosi grinned. “Come on, Ace.”
Ace jumped up happily. “Okay!”
Law watched them run off, then he stood, because apparently this was his life now.
And somehow, he wouldn’t change it, not even a little.
_______________________
Rosi had always hated being told she was too young.
At thirteen, it felt like one of the most insulting things anyone could say to her. Adults said it as if age were the same weakness, as if being smaller meant being incapable, as if she had never learned how to think for herself or take care of her own business.
It was ridiculous.
She was a pirate. Not yet, technically, but she would be. One day the sea would know her name, and no one would look at her and see only a child. They would see Monkey D. Water Rosi, daughter of Monkey D. Luffy and Trafalgar Law, a girl who belonged on the ocean.
The trouble was that everyone already saw those things.
They just saw the thirteen-year-old part too.
Especially her father. He said things like, “You’re not going alone,” and, “You need someone watching you,” and, worst of all, “You’re still a child.”
Rosi hated that one most of all.
So when Law told her she couldn’t go into town alone to pick up supplies for the ship, she decided she had no choice but to prove him wrong.
It was, she told herself, a perfectly reasonable plan.
She slipped away while everyone was distracted.
The Sunny was loud enough that sneaking off was easier than it should have been. Franky was shouting about repairs. Usopp was in the middle of some ridiculous story. Her papa was eating, which meant he was paying attention to absolutely nothing else.
Everyone was distracted. Except for one person.
“Rosi?” Ace called softly.
She froze. Slowly, she turned.
Ace stood a few steps behind her, barefoot and small and serious, his favorite stuffed animal tucked under one arm. He had messy hair, wide eyes, and the unnerving habit of looking far too much like their sire whenever he was suspicious.
Rosi let out a quiet sigh. “Ace.”
He tipped his head. “Where are you going?”
“Nowhere,” Rosi said at once.
Ace narrowed his eyes. It was honestly a little terrifying how much he resembled Law when he did that.
“You’re lying,” Ace said.
“I am not,” Rosi shot back.
“You’re doing the face,” Ace insisted.
“What face?” Rosi asked.
“The face where you think you’re being sneaky,” Ace said.
Rosi frowned. “I do not have a sneaky face.”
“You do,” Ace said immediately.
“I don’t.”
“You do.”
She stared at him and he stared back.
Then Rosi sighed. “Fine. I’m going into town.”
Ace’s eyes widened. “By yourself?”
“Yes,” Rosi said.
“Daddy said you can’t.”
“I know.”
Ace considered that for a moment, then nodded once. “Okay.”
Rosi blinked. “Okay?”
“Okay,” Ace repeated.
She smiled despite herself. Finally, a reasonable person.
“Good, now go back to the ship,” she told him.
Ace immediately grabbed her hand. “No.”
Rosi looked down at him. “Ace.”
“I’m coming.”
“No you’re not.”
“Yes, I am.”
“Ace,” she said again, warning in her voice now.
“You can’t go alone,” he insisted.
“That’s what everyone keeps saying,” Rosi muttered.
“Because it’s true,” Ace said.
Rosi stared at him. “You’re nine.”
“I know.”
“You can’t protect me.”
Ace frowned. “I’m not trying to protect you.”
“Then what are you doing?”
He looked genuinely confused that she even had to ask.
“I’m coming with you,” Ace said.
Something in Rosi’s chest softened, because that was Ace. He didn’t follow her because he thought she was weak. He followed her because, to him, being with her was the most natural thing in the world.
She was his big sister, his favorite person. The first person he looked for when he woke up. The one who taught him how to tie his shoes, climb trees, and sneak extra dessert from Sanji.
She was his whole world, and he was hers. Even if she would never admit it.
“Fine,” she muttered.
Ace’s face lit up. “Really?”
“Yeah.”
“Yay!” he cheered.
“But you have to listen to me,” Rosi warned.
“I always listen,” Ace said.
“You absolutely so not.”
“I do!”
“Ace,” she said flatly.
“...Sometimes,” he admitted.
Rosi laughed, and together they disappeared into town.
Law noticed exactly twelve minutes later, because apparently the universe hated him.
He stepped onto the deck expecting to find Rosi arguing with Luffy over something ridiculous. Instead, he found the spot where she had been sitting empty.
His eyes narrowed.
“Where’s Rosi?” Law asked.
The entire deck went silent.
Luffy looked up from his food. “Hm?”
“Where is Rosi?” Law repeated.
Everyone glanced around, then they all looked concerned.
Nami stood first. “She was here.”
“When?” Law asked.
“Ten minutes ago,” Nami said.
Law’s expression darkened.
“And Ace?” he asked.
The silence that followed was answer enough.
Robin sighed softly. “They’re together.”
Law stared at her, then, very calmly, he said, “No.”
Luffy stood. “They’re probably just exploring.”
Law turned toward him. “She disappeared.”
“She’s fine!” Luffy insisted.
“She’s thirteen!” Law snapped.
“She’s strong!” Luffy shot back.
“She’s thirteen!” Law repeated.
“She’s like me!” Luffy argued.
Law pointed at him. “That is exactly why I’m worried.”
Luffy opened his mouth then closed it, because, unfortunately, he knew Law had a point.
The problem with Rosi was that she was smart. That was what made her dangerous.
If she had been reckless, Law could have dealt with that. Recklessness was simple. Recklessness was loud and obvious and usually easy to stop.
Rosi was worse.
She planned. She thought things through. She looked at a problem and immediately started figuring out how to solve it. She got that from Law.
The trouble was that, with her Luffy side, her plans sometimes began with, I can probably do this, and ended with, Why is everything on fire?
This time was no different.
Rosi had found what she was looking for, a hidden path outside town, an old storage area near the docks, and exactly the piece of equipment she thought might help the Sunny.
She was halfway through figuring out how it worked when Ace tugged on her sleeve.
“Rosi,” he said.
“What?” she asked.
“You’re doing the face.”
She looked at him. “What face?”
“The one where you know something is bad,” Ace said.
Rosi looked away. “I don’t know what you mean.”
“Yes, you do.”
She sighed. “You sound like Dad.”
“I know,” Ace said.
That was not helping.
Before she could answer, the old structure above them gave a low, ominous creak.
Rosi looked up. Ace looked up. Then the whole thing shifted.
“Run!” Rosi shouted.
She grabbed Ace’s hand and yanked him backward just as the wooden beams came crashing down around them.
Dust exploded into the air.
For one long second, everything went still. Then Ace’s voice cut through the silence.
“Ace?” Rosi called.
“I’m okay!” he shouted back.
Rosi turned sharply. He was sitting behind a pile of broken wood, wide-eyed but unharmed, just scared.
Her stomach dropped.
“Ace,” she said.
“I’m okay,” he repeated.
“You’re scared.”
“No,” Ace lied.
“Ace.”
He looked away. “Okay. A little.”
Rosi moved toward him at once. “I’m sorry.”
Ace shook his head. “You were trying to help.”
“That doesn’t matter.”
“Yes, it does.”
“No, it doesn’t. I dragged you into this.”
Ace looked up at her with a seriousness that was almost unfair coming from someone so small.
And for a nine-year-old, he had a remarkable talent for making her feel like the child.
“You always do that,” he said.
Rosi blinked. “What?”
“You think you have to do everything.”
She went quiet.
Ace tightened his hold on his stuffed duck. “You think because everyone says you’re special, you have to be special all the time.”
Rosi looked down. “That’s not true.”
“It is.”
“Ace,” she said softly.
“You think you have to be like Daddy,” he said.
She froze.
“And like Papa,” he added, pointing vaguely, “because you’re both strong.”
Rosi didn’t answer. Because he was right. The truth was that sometimes she wondered if she was enough.
She had grown up on stories, about Papa, about Dad, about everything they had survived, everything they had accomplished, everyone they had saved. And sometimes, when she looked at them, she wondered if she could ever become someone like that.
Someone worth being proud of.
“I’m their daughter,” she whispered.
Ace tilted his head. “Yeah.”
“What if I’m not enough?” Rosi asked.
Ace looked genuinely confused. “Enough for what?”
“For everyone,” she said.
Ace climbed carefully to his feet and stepped closer.
“You’re Rosi,” he said.
She blinked. “What?”
“You’re just Rosi,” Ace said.
He smiled, small and certain.
“You’re my sister.”
Her throat tightened.
“You don’t care that we’re their kids?” she asked.
“No.”
“Why?”
“Because you’re you, and I’m me,” Ace said. “And that’s all that matters.”
And somehow, that was the thing that made her feel strongest.
Not being the daughter of legends, not being someone’s legacy, just being Rosi.
When Law found them, he was not calm. Not even a little.
The second he saw them, he crossed the distance in a few quick strides and pulled them both close.
Rosi went rigid at once. Law was not a hugger, not usually.
“Do you have any idea what you did?” he demanded.
Rosi looked down. “Yeah,” she said quietly.
“No, I don’t think you do.”
“I’m sorry.”
“You could have been hurt.”
“I know.”
“You could have gotten Ace hurt.”
Her face fell. “I know.”
Ace immediately stepped forward. “I’m sorry too.”
Law looked at him. “You didn’t do anything.”
Ace frowned. “But I followed her.”
Law exhaled through his nose. Because somehow, even when he had done nothing wrong, Ace still found a way to apologize.
“You were worried about her,” Law said.
Ace nodded. “Yeah.”
Law looked at both of them for a long moment, then sighed. “Just tell us next time.”
Rosi nodded. “I will.”
Ace nodded too. “Me too.”
Luffy arrived a moment later, breathing hard and looking thoroughly alarmed. But the second he saw them standing there, safe and whole, his expression softened. He pulled them both into a hug.
“My kids,” Luffy said warmly.
Rosi smiled. Ace hugged him back immediately.
Luffy looked over at Law. “They’re good kids.”
Law looked at the two children, one who caused trouble and one who followed her straight into it, both of them gazing up at him as if he had hung the moon.
He sighed.
“They are tiny disasters,” Law said.
Luffy grinned. “Yeah.”
He tightened his arms around them both.
“Our tiny disasters,” Luffy said.
And somehow, Law couldn’t argue with that.
Not when they were his.