Hey Guys! Haven't written in awhile. But I got inspired recently, so I'm happy! Anyways, I read a volume of One Piece and Case Closed in the same day, and got this idea in my head. I hope you like it! Also, I don't own anything with One Piece or Case Closed, enjoy!

Jimmy Kudo stood out on the deck of the navy ship, anxious to get to this Marineford Island. He had no idea where he was, or what the hell he was supposed to do, he just knew that this wasn't a good situation. He looked over his shoulder at the anxious soldiers that were watching his every move, and had the chain that connected to his shackled wrists that were bounded behind his back. Many thoughts raced through the young detective's head: who were these people? Were they connected to the Black Organization? Where was he? How did he get here? Did they know who he was. Escape was meaningless when you were just going to drift out at sea aimlessly, especially when you had no idea where you were to begin with. Turning to the guard, Jimmy Kudo, known as Conan Edogawa spoke. "Excuse me, mister?"

"What?" The man replied.

"Where are we going?" Conan asked as childishly as possible. Hopefully, his identity was still concealed.

"We told you, you're going to Marineford, that's all you need to know." The man's partner said gruffly. Conan pouted and turned back to the ocean, from what he could tell he was on some sort of military vessel, but he strangely couldn't recognize it. This only made him more anxious. He inwardly cursed himself, how the hell could he have allowed himself to get caught like this? He was chasing down a Black Organization member, and he suddenly found himself unconscious from a tranquilizer dart. What happened? Were Rachel and the others okay? His thoughts stopped when the ship suddenly docked. The guard motioned Conan forward. "Come." The detective followed obediently; luckily he still had a few gadgets on him, which he found strange. Why would the Black Organization give him the privilege of allowing him tools? He looked around his surroundings, rather astonished. It looked like an entire Naval base on a huge island. It would've been something to marvel at if not for his current situation. Noticing that the main building had a Japanese style to it, he wondered if he was in the Pacific somewhere, but his mind quickly changed once they made him actually enter the building. He was surrounded with the Japanese language, but none of the familiar customs and items he was used to, it was a general white hallway with golden sashes hanging from the walls. They had portraits of past commanders of the Navy, as well as various award cases to honor themselves upon their accomplishments.

Noticing that they were going into an elevator, Conan paid attention to how many floors were actually in this place. He glared, 30 floors; great. Not to mention the place was massive, it'd have various hallways and passages he'd have to memorize. His eyes widened slightly when he noticed they stopped on the top floor; they were introducing him to their commander. They were awfully confident. Walking up to an office, one of the guards knocked. "Fleet Admiral Sengoku-sama! We have brought the boy!"

"Good. Bring him in." Conan heard the voice answer. He suddenly felt himself lifted and harshly thrown into the room. Conan quickly sat up and took in his surroundings. He was surrounded by approximately six people, excluding the guards. All were freakishly tall and seemed to be in high standing in the facility. Glancing at the desk, he saw a man in his fifties, with a black afro, glasses, and a long, braided, Chinese beard. Judging by the badges he had, Conan guessed he was in charge. "Ah. Conan Edogawa, pleasure to meet you. Or should I say, Jimmy Kudo?"

"…Who are you?" Deciding that playing dumb was obviously useless here. "You're with the Black Organization, aren't you? What is this place?" Conan demanded with flared eyes.

"Calm down." Sengoku raised a hand. "Though it's true we have ties with the Black Organization, we aren't with them as allies, for they do not uphold our standards of justice." Seeing the boy's confusion, the Admiral continued. "Let me put it this way, we wish for your service, and in exchange, your life and secret will remain safe. As well as returning home to your beloved Rachel Moore, and your friends. They simply wanted us to kill you." Sengoku reasoned as Conan sat there shocked, and looked to the floor and clenched his fists and teeth.

"What do you want?" Knowing he had to admit defeat for now.

"Let's introduce ourselves first, shall we? After all, you need to know who's in charge of you. Excluding a friend of mine, the highest officials in the Navy are in this office. I am Fleet Admiral Sengoku, I am in charge of the Navy. Those two men on the couch are two of the four admirals. The one on your left is Kizaru, the one you're right is Akainu, and the man laying on the other couch is Admiral Aokiji. The three Vice Admirals in here are, Onigumo, Tsuru, and Strawberry." Strawberry? Conan knew it most likely was a code name. "These people will be watching over you and supervising your work, know that even if you do manage to escape from us, you have no way of finding your way home." The look on the boy's face showed his disbelief. "I'm afraid I can't say much, but you're on an island, surrounded by waters that can claim you in less than a minute, in enemy territory, and you haven't the slightest idea of where you are. You should also note that the Black Organization will be contacted if you show disobedience, in which case, your friends and family will start disappearing. One by one."

"You bastard!" Conan yelled, only to be harshly kicked in the stomach. He flinched and looked up to a man in a baseball cap, his name mentioned was Akainu.

"Mind your manners." He said sternly and looked down at Conan. "You're in a different world now kid, literally."

"…What?" Conan knew he couldn't have heard right.

"That's another reason why it's impossible for you to escape." Sengoku interrupted. "There's nowhere to escape to. You're in our world now, Mr. Kudo. Your stay here can either be pleasant or horrific, the choice is entirely up to you. As I said, no one outside this room knows your identity, or that you're even here. Your secrets are safe with us, so long as ours are with you." Sengoku pointedly glared at the stiff boy. "Cooperate, and you will be back with your friends and family in no time, no harm will come to them, and you can pretend this never even happened. So, how about it, Mr. Kudo? Will you cooperate with us?"

Conan glared but nodded reluctantly. "What do I have to do?"

"I understand that you're a famous detective in your universe, Mr. Kudo." Sengoku said, getting a massive file out from his desk. "Able to solve any case with in the blink of an eye, even being able to tell who the culprit is by just looking at the crime scene, very impressive. The Black Organization contacted us, telling us about your talents. In exchange for some resources, we asked for your service. We need you to solve a mystery. A simple one, compared to every other case you've seen, I'm sure."

"What's the mystery?" Conan asked carefully.

"I want you to locate One Piece- the lost treasure of Gol. D. Roger." Sengoku smiled. The vicious game had begun.