Hey guys! So here it is, the final chapter of Case Closed: Returning the Missing One Piece. Thank you so much for your support and reviews. I'm not sure how people will react to this ending, but I had my heart set on it, and I don't plan on changing it. Please save all comments and questions until after you read the whole chapter. Without further ado, here's the final chapter! Read, enjoy, review!

Disclaimer: I don't own One Piece or Case Closed

Conan took a deep breath, hardly believing what was happening…he could not believe he was doing this again. He felt a hand on his shoulder, and saw it was Sabo.

"Don't worry…we're all nervous about this." Sabo smiled. "You know…you don't have to come if you don't want to."

Looking back at his friends and family, awaiting for the proper configurations of the Gateway to open, he smiled back at Sabo. "No…I have to go back…I need to go back."

Nodding, Sabo looked over at Lupin. "Are you sure, you and your group don't wish to come?"

"Intimate goodbye scene aren't really any of our things so…" Lupin responded. "We'll be waiting for you…all of you."

"We will safeguard this portal until no longer needed." Ishikawa insisted.

"But you'll never get this opportunity again." Conan pointed out. He had felt great gratitude towards the thief, and it felt wrong that he and his gang were leaving themselves out.

"I'm Lupin the III, kid. The fate will always favor me." He reassured.

Conan smiled and turned back to Fisher Tiger, who was lining Hody and his men up. Despite the situation, the detective couldn't help but feel that Hody and his men were very much homesick. Otohime had chatted with Fujiko to pass the time, but it was obvious the queen was very anxious to see her family.

"Everyone who is going through the portal, get ready!" Haibara barked, typing away at the blinking keyboard. As everyone started to gather around, she frowned when she saw Agasa not joining them. "Doctor?"

"One of us has to stay behind to insure that the machine is operating in its proper function…you and I are the only ones here qualified to do this." Agasa gave her a gentle smile. "I know you were involved in the early works of this project, so please…go with them…you've earned it."

"Doctor…" Haibara clenched her fists, and immediately bowed. "Thank you!" The young scientist joined the group, leaving the old man.

Conan frowned as well when he saw that Agasa would not be joining them, but one wave from him, told the detective all he needed to know. Feeling a sudden gust of wind, he turned around and saw a bright spiraling light from the spiral machine. Gulping, he tried to swallow his anxiety along down with his excess saliva; his legs were trembling and he found himself slightly paralyzed.

Suddenly feeling himself being hoisted up, he looked down to see his father smiling at him. Vivian help stabilize Conan on his father's shoulder, and offered her own smile. From this point, he saw Rachel and her father giving him the same look, giving him the same confirmation. They had all come this far, so it was only natural to feel anxiety at the end of a journey.

"Good luck, Kudo." Conan blinked and turned back to Heiji. "Don't give me that look, Kudo! Someone needs to stay behind and collect evidence! So go ahead, take your time saying goodbye to your pirate friends! I'll be here getting ahead of you by collecting evidence on the Black Organization!"

"Hattori…" Conan smiled. "Thank you…truly…thank you."

"Don't thank me. I've got a lot of making up to do." Heiji smiled. "Besides…someone has to stay behind with this old man." He gesuted to Agasa.

Agasa would have rebuttled, but he was busy finalizing the calculations. "It's all set, now go!"

The first to jump was Fisher Tiger, who was leading Hody Jones and his men on chains. The next was Otohime, then Sabo; followed by Haibara, Rachel and Richard Moore, which left them. Sighing, he nodded at his parents. Walking forward, he felt the portal pull him through, and then felt the familiar feeling of disintegration. He briefly wondered if dying felt like this…a total free fall.

XXXXXXXX

As soon as Conan and his parents landed, he was immediately surrounded in the familiar exuberant luxury, that could only be found in a Tenryuubito palace. Panicking slightly, he quickly glanced around himself for guards, only to be set down on the ground by his parents. His eyes widened at the sight…in front of him were very familiar faces…he easily recognized the unifomrs of the Navy, including…Fleet Admiral Aokiji.

The man, who now let his hair down, smiled gently and walked up to Conan and his group. He knelt down put a lazy hand out. "Welcome back…Detective Kudo."

Conan smiled, and shook the offered hand. "The honor is all mine, Fleet Admiral. These people are from my world…these are my parents, Vivian and Booker." His father shook Aokiji's hand, and Vivian curtsied. "And this is my best friend, Rachel…and her father, Richard. They helped me a lot when I first got morphed into a kid. And this is Anita Haibara…" He gestured to the girl who was gawking at literally everything she could. "If not for her brilliance, we would not have been able to return."

Nodding, Aokiji looked directly at Conan again. "It's not that you aren't welcome here, but why have you come back?"

Nodding, Conan began. "I'm not entirely sure what you've been told, but…there was an invasion of fishmen in my world, and I came to bring back the heros who helped save it." He looked around for Sabo and the fishmen, but found that they weren't anywhere around. "And now they're gone."

"If you are talking about the Tophat boy and the fishmen, they left already." Kizaru spoke up from a corner. "The fishmen all jumped into the water, and the boy simply ran down the hallway, pulverizing marines. He's lucky that Sentomaru-kun warned us of your arrival ahead of time, otherwise we actually would have tried to stop him."

"What exactly did Sentomaru-san tell you?" Conan asked carefully.

"Basically what you said. That somehow, there had been a large amount of fishmen had been allowed to invade your world, and that they were being led by none other than Hody Jones." Kizaru explained. "Additionally, we received intel there were human traitors from our world who went over to your side to take over. So reasonably, when that Vermouth-woman told us the only reason you were able to survive was due to a boy in a tophat, as well as two fishmen which are supposed to be deceased, we were quite surprised."

"I see." Conan's shoulders slumped. He should have known better than to expect Sabo or Fisher Tiger to stay quietly if there were marines in an area. A curious notion came into his head. "Excuse me but…how long in between were the people who arrived?"

"You guys were exactly fifteen minutes apart." Sentomaru answered. "Time does some weird shit when people go between these worlds."

"How long ago did Vermouth contact you?" Vivian surprisingly spoke up.

"For us…it was two days ago…for you…no idea." Sentomaru shrugged, and went back to the machine. "Doesn't matter, it gave us plenty of time to prepare for your arrival."

"You were expecting us?" Rachel piped up.

"Nah, just Kudo. But the party's big enough for all of you, so I don't see a big deal." The scientist huffed.

"Party?" Richard blinked.

"Yeah, this kid's a hero in our world, what were you expecting, an ambush?" Sentomaru snorted. "Anyways…I have to stay here to monitor this thing, so good seeing you again, Kudo."

"Thanks." Conan smiled, curious as to who was at this 'party'.

XXXXXXXX

After following the marines down to a certain hallway, they abruptly stopped at the entrance of the palace. There, Conan was met with the familiar faces of Helmeppo and Coby…they were huge now! The pink-haired boy was nothing like what Conan remembered. "Conan-kun…welcome back." He smiled politely and then at the boy's group. "And you must be Conan's friends, welcome."

"Coby-san…Helmeppo-san…" Conan walked forward and grabbed both their hands. "You…both look great."

"Thank you…Admiral Garp's training paid off." Coby laughed lightly, and then placed a hand on the door. "Due to diplomatic agreements, all marines and World Government officials are banned from entering the front terrace and pierre of this palace. They however may come in, so long as you grant it."

"Diplomatic agreement?" Haibara repeated.

"Yeah, you'll see when you get outside." Helmeppo huffed. "Anyways…Chairman of Cipher Pole, Rob Lucci, sends his regards, but was unable to attend because of honeymoon. Additionally, Mrs. Margueriete Lucci sends her regards, and his teammates were too busy covering his work."

Conan's eyes widened at the revelation. "I see. Tell them I said congratulations."

"Will do." Coby nodded. "Now then…your party awaits."

XXXXXXX

The second the golden gates opened and closed, Conan understood exactly what they meant by diplomatic agreement; every single pirate crew he had met was here. His heart swelled and looked around for the Strawhat flag immediately…his face fell when he didn't find it. Were they not here?

"Detective boy!" Before he could think anymore, Conan was bombarded by a hug from a familiar okama king. "Your back! I thought it was fally! But your back! And you must be his family! And ooh…a girlfriend?! Lovely!"

"Err Jimmy…care to introduce us?" Rachel asked uneasily.

Regaining himself, Conan smiled. "Yeah…this Emporio Ivankov, he is a part of the Revolutionary Army, which is lead by Monkey D. Dragon. The father of my captain."

Re-introducing himself to the Revolutionary Army had been easy, if not a bit awkward. While they did appreciate what he did in the end, he still thwarted their efforts for war. But an approving nod from Dragon had been enough to let Conan know he was forgiven. Then came Law and Red-Hair's crews…they had scolded him for his recklessness, but were welcoming non-the-less, but then came the one he was most nervous over- Whitebeard.

Slowly…he was led onto the massive ship; his group close behind. They were met with smiles, waves, and cheers, and they eventually were lead to the strongest man in the world himself. Conan had to resist the urge to laugh as Richard's jaw literally dropped at the man's size; up until now, the strangest thing they had seen was the okama king. Whitebeard was literally the size of skyscraper, so their reaction was understandable. Rachel's eyes were as wide as saucers, and his parents had to suppress their gasps.

"Welcome back, Detective Brat." Whitebeard smiled, though Conan could not help but be worried from the old man's appearance. There were even more tubes and wires connected to the man, and his breathing appeared to be labored. Marco stood faithfully at his side, and smiled.

"Yo!"

"Marco-san." Conan bowed to the man, and turned back to Whitebeard. "Thank you for having me on your ship once again, sir. Please…meet my family…these are my parents, Booker and Vivian, my friend Rachel and her father, Richard, and this is my friend, Anita Haibara. Guys, this is Captain Whitebeard, of the Whitebeard Pirates."

"A-A pleasure!" Richard stammered.

"Nice to meet you." Rachel, Haibara, and Vivian curtsied.

"Thank you for taking care of my son while he was here." Booker bowed deeply.

"Hehe…he knew his place." Whitebeard nodded.

Conan frowned when he looked around, and his eyes widened when he spotted a familiar tophat in the crowd. Instantly, he sprung from his spot and ran forward. His eyes lit up; it was who he thought it was. "Sabo-san! Ace-san!" The two pirates turned to face him with wide smiles.

"Kudo!" Sabo greeted, but was glomped by the detective.

"Wow, he actually gives hugs." Ace snorted, but was soon met with one of his own. He smiles, and kneels down to Conan's level. "Thanks for bringing my brother back, thought he was lost forever."

"No…he helped save my world, it was the least I could do." Conan shook his head. "We can call it even."

"Nope. We're not even. You saved our world and brought back my brother." Ace smiled. "Speaking of which…I think he should be here about now. Hey Gramps, you do the honor!" Ace turned to a surprising face on a pirate ship; finishing off his swig of rum was Monkey D. Garp.

"About time you showed up, my grandson's getting impatient! Though its his own fault for arriving so late! His fault for not following his loving grandfather's advice!" Garp pounded his chest.

"Garp-san!" Conan smiled and ran up to him. "What are you doing here? What about the agreement?"

"Politics are for the weak; no piece of paper can keep me away from my grandsons! Speaking of which, you've got some training to catch up on squirt!" He gestured to Sabo, who paled considerably, while Ace laughed at his friend's upcoming toture. "But before that…" Garp fisted Conan's shirt, and swung his arm way back.

"Uhh…Garp-san…what are you doing?" Conan sweat-dropped.

"Jimmy!" When his mother tried running up to them, Garp pitched.

"GRANDSON! CATCH THIS!" Garp launched Conan into the air, and propelled the boy hundreds of feet out into open water, with no signs of stopping.

"Jimmy!" Rachel shouted over the edge.

"Don't worry, he'll be fine. Look." Sabo pointed to a ship in the distance.

Meanwhile, Conan could not help but twitch irritably at what just occurred. 'Only in this universe, would he not be court martialed'. The detective closed his eyes and braced himself for impact.

STRETCH!

Conan suddenly felt himself yanked from the air, and land against someone's body. As soon as the arms retracted into proper place, the detective boy immediately started tearing up.

"GRAMPS! NO THROWING MY CREWMATES!" That voice…was unmistakable. Slowly, Conan turned his head to look at the face of the Strawhat Captain.

Noticing the shift, the rubber boy looked down at Conan with a grin. "Conan! Welcome back Conan!"

Immediately, the detective embraced the rubber boy; no words could describe the feelings he was experiencing right now.

"Welcome back, detective." Conan blinked and looked over Luffy's shoulder. His grin broke out wider when he saw who was looking at him; they looked extraordanarily different; especially Ussop ad Franky, but it was them. The only one who looked the same was Luffy; he held a giant scar on his chest, and he now wore long sleeves, but that grin had not lost its vigor...had not lost that inspiring magic. It was truly the Strawhat Pirates.

Swallowing a happy lump in his throat, he grinned at them as well. "What took you guys so long? You're the last ones here." Luffy put him down, and he ran to the crew. Each gave him a hug or hair ruffle, and other than Zoro, was filled with endless chatter, though he did smile at the boy.

Luffy smiled brightly at Conan. "So that means you're staying right?"

XXXXXXXXXX

The celebration was over now, other than Ace and Sabo, only the Strawhat pirates escorted Conan and his group back to the portal. Each of them had enjoyed the experience greatly; his parents got to thank every single pirate who kept him alive, Rachel and Richard had the pleasure of meeting so many interesting people, and Haibara got to experience something no other scientist would ever claim to do. It was a good turnout for Sabo too, he decided to sail with Luffy and his crew until they reached their next island. There, he'd leave and most likely start training; he had serious work to do in order to enter the New World. As for Fisher Tiger and Otohime, they did not show up until the end of the party.

The fishmen weren't there long, but King Neptune had done something no one would ever see again- he bowed. He bowed graciously to the detective…"Thank you." Neptune told him that he would always be welcome in his kingdom, and that they would think of him to remember the good of humanity. From what Conan had been told, Fisher Tiger would be helping rebuild the fishman districts that had been terrorized by Arlong and other extremists; he had serious reforming to do.

Conan was brought from his memories as soon as they were brought back to the Gateway; Sentomaru remained stoic and turned on the machine. "Before you go, I have to ask since we need to know in order to make a certain decision. Haibara-chan…what are your intentions with this research? What do you want to do from here?"

The girl rose a delicate brow. "I assume you mean if I am going to destroy the machine on my side or not." Sentomaru nodded. "Of course I am. I've got what I came here for, and managed to gather data into the direct anomaly of string theory. No other scientist has done this."

"But, don't you want to come back eventually?" Ace pointed out, sending a worried glance at Luffy.

"No. Beyond the conclusions I was able to draw from this trip, I have concluded that this technology is too dangerous to exist. Innocent people were severely hurt for these ambitions, and had nearly brought the end of two worlds. Destroying the Gatway is the only logical option." She glanced at Kudo. "Regardless of what anyone decides, I have made my decision, but I will not force anyone to go along with it. So if anyone has any second-thoughts of where their home is, I suggest to sort them out now." She walked up to the entry way and turned to the rest of the group.

"What she said." Richard grumbled, and followed suit; he was more than ready to go home after all the freaks and weirdos he met today.

Rachel knelt down and gave him a big hug. "...I'll accept whatever you decide Jimmy." She then let go and followed her father, though Conan easily caught the tears, trailing down her eyes.

Vivian and Booker smiled and gave handshakes to the Strawhat crew. Vivian smiled gratefully at Luffy, and gave him a big hug. "Thank you for protecting my son…I am forever in your debt." She let go, and walked to the platform. Booker gave Luffy a strong handshake, and pat him on the shoulder before departing.

All that was left was Conan, he had been avoiding Luffy's question the second he asked it, much like how he was used to doing with his family.

"You're not staying, are you Conan?" Luffy's voice held no betrayal or malice, but Conan easily detected the sadness.

Looking to the ground, the boy breathed calmly before answering. "No, I'm not."

"Why?" Luffy's voice cracked; his face was hidden under the hat. His crew had figured that Conan would choose to go back, but it still pained them to see their captain like this.

"We both know the answer to that, Luffy-san." Conan smiled in spite of the situation. "I cannot fight adequately and I serve no use to any position on a pirate ship; I would be nothing but deadweight-"

"Stop it." Luffy growled, earning a confused glance from the detective. "No one in my crew is allowed to put themselves down, don't think you're any exception."

Conan's eyes widened, in a shaky voice he asked. "I am…still apart of the crew?"

Luffy frowned and knelt down to him, forcing the boy to look at him. He had to face his Conan, his sadness and tears could wait; his crewmate needed him. "I meant what I said the last time we met. Regardless of what world you're in, you'll always be apart of my crew. I just wish…you'd stay in the same one with us."

Nodding stiffly, Conan bit his lip. "I know."

"You're not coming back after this, are you?" Luffy asked with the same tone as before.

Unable to look at him, Conan croaked. "No, I'm not."

"I can understand you not being able stay forever, but why…why can't you visit? Why can't you leave the machine working?" Luffy hugged him, the same way an older brother his younger.

"It's too dangerous, Luffy-san." Conan answered sadly. "The same thing that happened to me could happen to someone else. Think of what happened to Sabo-san, Tiger-san, and Otohime-san."

"We can fight it! Together! We could prevent it!" Luffy tried to argue.

"Luffy-san...Captain…" Conan interrupted softly, he looked up at Luffy with a sad smile and shook his head. "It's not going to happen."

"I don't want you to go." Luffy sniffled, and hugged the boy close. It was not fair, he just got his crewmate back, and now he was leaving again.

"I know, but…I have to. Both if us know, I have to." Conan smiled, tears streaming down as he hugged the taller boy back. "It's been an honor, my captain. If not for the things you taught me, I would have become my own worst enemy, so for that…thank you."

Luffy jerked back slightly and looked Conan directly in the eye. "You'll always be a Strawhat, you hear me?!" He shook the smaller one slightly.

"I hear you!" Conan shouted, shaking him back. He gave Luffy a confident smirk. "I promise! No matter what universe I'm in, you'll always be my captain!"

Responding his signature D grin, Luffy stood up and clenched his fist. "Okay! That means that you have to achieve your dream of becoming your world's greatest detective! Never give up! And never betray yourself! Do us proud, Conan!"

"Always, my captain! Always!" Conan nodded and bowed slightly with a clenched fist. "As long as you and our nakama follow the same!"

"You don't even need to ask, Kudo." Robin nodded.

"Seriously, who do you think you're talking to, kid?" Nami poiuted.

"We're way ahead of you on that one." Ussop nodded.

"My music will only get better, Yohohoho!" Brook lifted his hat.

"We promise, Conan!" Chopper cheered.

"I have two beautiful ladies, and ingrates to keep alive." Sanji puffed his cigarette.

"I have never lost my path, damn kid." Zoro nodded.

"Even with Sabo back, I promise to become the next pirate king!" Luffy finished, and held out his hand. "Friends and nakama forever, right Conan?!"

Looking at the hand, Conan grabbed it and shook it with the same conviction. "Right!" Conan looked up at his captain, and he knew he would never see him again, but it didn't matter because he would never forgot him. He would never forgot any of them. He would never forget anything from this world, but would treat it as they were there with him, fighting alongside him every day.

Because it was true; regardless of what universe these two were in, they would forever be comrades. Conan knew that if he ever fell into a dark place again, he knew that the second he thought of Luffy, he would find a way out. He'd find away to save everyone, and he would continue his way to be the greatest detective.

Conan knew that Luffy would think of him if the captain needed to figure something out, and Conan felt honored by this. He truly felt as that he was awarded the greatest honor to have even met the future King of the Pirates.

Review Please! Thank you again for your support! I'm glad you all loved this story! As far as the idea of a third installment in this series goes, I am definitely going to say no. I know I said I would not do a second story, but I am adamant about no third story. I know some were looking forward to Conan joining Luffy, but I never intended that to start.

Note: In this story, Luffy got the x-scar from a different fight with Akainu, I just decided to include that feature to keep with New World.

Several people had requested I consider doing different crossover stories with different series. I am willing to consider this, but I will warn you all that I need a break, and I will not post another story for awhile.

Third, some people questioned about whether or not I';d let them start a spin-off series or stories to the Case Closed x One Piece series. Please PM me about those ideas if still interested.

Lastly, you can review or PM any comments, questions, or any other underlying concerns about the stories. Or just general discussion questions you may have. I truly loved writing this, and I loved discussing it with you all. Hope you guys enjoyed it! Later!