I had started this story quite a while ago but had not gone beyond a few hundred words. With my muse for my other stories on a little vacation, I found myself flocking to this little fic.

So, here I am, trying my hand at a KHR and Castle crossover. This is set somewhere in season 4 of castle and a couple of years after KHR ended. Except, there is no Neo Vongola crap. It's the proper Vongola and the Tenth generation.

So, well enjoy.

And review. Don't forget that.

Mafia Heat: 1

The hotel was one of the foremost hotels of New York. So, it was always full of people moving around. The only difference this time was that most people were either in navy blue uniforms or wore blue wind cheaters with the word FORENSICS on their backs. Hence, the man wearing a thousand dollar suit, who would have been at home in the lobby any other day, looked out of place in the crowd. Rick castle made his way to the elevators with a cheerful grin and pressed the relevant button for the elevator to take him to the crime scene.

In the penthouse suite, Detective Kate Beckett was leaning over a body when the smell of coffee filled her nose. She smiled. It seemed her 'partner' had arrived. She suppressed her smile and returned her face into her normal face when she dealt with Castle- mildly disapproving with a hint of amusement. She accepted the cup of coffee that had been held out to her.

"Morning, Castle." She greeted.

"Certainly is a good morning, Beckett. Nothing like a mystery to start a new day." Castle grinned at her as he surveyed the crime scene. "So, what do we have here?" he asked.

"Oh you're going to love this one, Castle." a blonde man in a grey suit walked towards them.

"Hey Ryan!" Rick greeted his friend. "What do you mean I'm gonna love this case?" Det. Beckett rolled her eyes as Ryan told Castle what they had managed to piece together.

"The hotel manager told us that this suite was booked under the name of a Michael Valmer. Last night at nine, three men showed up and asked for the room. One of them was Vincent Rossi. The other two were probably his bodyguards. " Ryan began reading from his notebook. He had just mentioned the name when Castle interrupted incredulously.

"Vincent Rossi as in Vincent Rossi, the son of Benito Rossi, the head of the Rossi mob family?"

Ryan grinned and nodded.

"Told you that you were going to love this one, bro."

"Is he one of the victims?" Castle asked as he peered towards the area of the room where a few forensics were standing over another dead body.

"Yeah." Beckett sighed as she nodded towards a third body that was in an overturned easy-chair, partially hidden from view. Only a pair of expensive leather shoes were visible to the trio.

"Anyways," Ryan continued, "as I was saying, Vincent Rossi and his guards went up to the suite and left instructions at the front desk to inform them when someone came for the room. At nine thirty, another guy came and asked for the suite, so the witness on the front desk sent word up to Rossi. Now this is where it gets a little weird. Rossi himself came down to escort the guy upstairs, and according to the witness, he was in some serious ass-kissing mode." Ryan paused and looked at Beckett and Castle. Beckett frowned at this information. She didn't know as much about the mob as the Organized Crime unit, but she had heard that Vincent Rossi was a typical spoilt second generation Mob brat. Too much swagger and too much violence. Not a guy who would kiss anyone's ass. This meant the guy that came had to be a big shot. Castle voiced her thoughts to the room.

"I know bro, I thought so too. So, I checked out the guy." Ryan spoke as he gestured them to follow him. They made their way to the body, next to the mini bar counter, where the forensics were wrapping up. "Give us a minute, guys." He spoke to the forensics and they nodded and moved away.

Castle looked at the body of the man lying on the carpet. It was obvious that he had died of the bullet wounds right over his heart and his head. Other than that, the guy was as ordinary as they came. He didn't even look rich. All his clothes were normal. Not shabby, but not swanky either. Vincent Rossi's shoes probably cost more than this man's complete outfit. Certainly not like a big shot.

"Weird, right?" Ryan asked them as they looked the body over.

"He certainly doesn't look like the man I had imagined him in my mind." Castle offered. "I had thought customized suit, shoes, Rolex and an overall impressive face. This guy wouldn't look out of place in a subway during rush hour."

Beckett agreed with her partner's assessment. She, however had more questions for Ryan.

"Who is he?" She asked.

Ryan consulted his notebook and answered.

"Found his passport on him. According to the ID, our guy is Carlo Messi, Italian citizen."

Beckett groaned. A foreign national. Great. Extra red tape.

Castle on the other hand, was visibly excited.

"Italian. That's so cool. And, he was meeting the Mob. Maybe he is from a Sicilian Mafia." He spoke gleefully. "Oh my God, this case keeps getting better and better."

Beckett and Ryan shared a look. Ryan smiled and said to Beckett.

"You want to tell him, or should I?"

" Tell me what?" Castle asked as he turned towards his friends.

"It's not going to be like what you're thinking, Castle." Beckett began. She gestured to the bodies as she continued in her slow style she used to explain things to Castle. "Just the fact that Rossi is one of the victims, is going to get the FBI involved. They will waltz in and try to run the show. There will be jurisdictional problems, egos will clash. Then add to it that a foreign national was killed. His government will want to be kept in the loop, not to mention it's going to multiply the red tape and paperwork by three times."

Castle stood silently for a few moments as he digested this piece of information. Then in authentic Castle style he started questioning everything.

"The last time we worked with the FBI, we didn't have these kind of problems. Agent Shaw and our team got along fine." He complained.

Beckett rolled her eyes at Castle's selective memory. It might have worked out in the end, but it had not been all rainbows and sunshine.

"That was because Captain Montgomery handled all that stuff. He was on good terms with Agent Shaw's boss. Gates, on the other hand, is not as liked as him. She is ambitious, so she is likely to want the credit, which Montgomery had no interest in." She countered Castle's arguments. "Trust me, Castle."

All three stood and contemplated what they had just discussed when the fourth member of their team arrived with the Medical Examiner.

"Hey bro!" Esposito greeted Castle. "You're going to love this one."

"Already said that." Ryan grinned at his partner.

Castle returned the greeting and turned to Lanie with a smile and nodded at her too.

"So, what does our beautiful ME have for us?" He wagged his eyebrows at the woman.

"Charming as always, I see, Castle." Lanie shook her head but smiled at the writer. "Cause of death for all of them were multiple GSWs." She pointed to the body at their feet.

"These guys were all blackjacked." Esposito said as he pointed to the pattern of the gunshots on the dead man. Castle made a questioning face, so Esposito explained, "Military nickname for triple tapped. One bullet each to the heart, sternum and the head."

Castle made a funny face, to which Esposito shrugged. "I don't make the nicknames, bro."

"It's a professional hit." Beckett nodded in understanding. Esposito nodded.

"Not only that, the guy is pretty good. From the way the bodies are situated, it was over within ten seconds." He added.

This announcement was met with silent nods of agreement. Esposito looked a little disturbed as he looked around the room, calculating something.

"Something on your mind, Espo?" Beckett asked him. Esposito looked at her with a grim expression.

"I take it back. The guy isn't good, he is beyond good." He waved his hand towards the entire room.

"Why, bro?" Ryan asked as he looked around the room, following Esposito's hand.

Esposito chewed his lip as he moved to stand next to them, so that Ryan and Lanie were on his left side and Beckett and Castle were on his right. Then he gestured them to follow him. The group went to the front door of the room.

"He entered through here, right?" He said as he raised his arms parallel to the ground, pointing in the forward direction, forming guns with his two fingers. "Since all the bodies are over there, he obviously entered without any of them opening the door to him."

"He had a key." Castle said as he glanced towards Kate. She nodded and said, "We'll have to get a list of all the people who have keys for the suite." She then nodded to Esposito to continue.

"The first to get hit was Rossi." Esposito said as he made as to shoot using his finger 'guns'.

"Why Rossi?" Beckett asked.

"Notice how he is still in his chair, overturned, but perfectly in the sitting position? If someone else had been shot first, Rossi wouldn't have been sitting in his chair, waiting for his turn. He would have lunged for cover. It's an instinct, you see someone get shot, you run for cover. Another thing, notice his bodyguards. One guy was on his knees, trying to duck behind the sofa when he took one to the head. The second one of his body guards had his gun out. He was probably the last, if he had the time to draw his weapon. Our big shot was most probably the second, as standing from here, his position was most exposed after Rossi. Their reaction time was very less. I estimate 5 seconds tops."

The others took this information in. Castle spoke, "In your opinion, all this happened within 5 seconds?"

Esposito nodded.

Castle whistled.

"Once every one was down, our boy made his way to each one and blackjacked them." He let his arms down back to his side.

"Meaning that our killer could have spent less than a minute in this room." Beckett sighed. "If he was aware of the meeting beforehand and the suite number, he would have been in and out of this Hotel within minutes."

"That means he probably wouldn't be remembered by any of the staff." Esposito added.

Ryan took out his phone and said, "I'll call my old friends in the OCU and get some info on who would want Rossi whacked." He moved away from the group, dialing on his phone.

Castle turned to Beckett and asked, "Isn't there a camera right at the entrance and exit?"

"Yeah, so?" Beckett asked.

"So, if our guy really did come in and go out within minutes, he will stand out in the video, right?" Castle said raising his eyebrows. Beckett looked at the writer.

"It will certainly narrow down the list of people, if our guy really did arrive and leave within minutes. He could be a guest in the hotel for all we know."

Esposito shook his head.

"Highly unlikely. This guy is almost certainly from military background, probably special forces, looking from the display of high level of skill." Esposito looked around the room. "It would be stupid to stay where we might want to interview him or get a chance to lift prints."

Beckett sighed. What Esposito was saying made sense. This was why she didn't like professional hits. Usually the killer left town before the police could get any solid leads. Unless some paper trail for the money was found, it was unlikely that the actual killer would be apprehended. The one who paid the killer was usually found out, but rarely, if ever was the killer found. She realized that Ryan had come back and was saying something.

"What? I'm sorry I was thinking."

Ryan nodded and repeated, "I said that this may start a mob war." He pointed towards Rossi's body. "Benito Rossi isn't going to take it lying down."

Castle turned back to the body and said, "You friends think this was done by a rival family?"

"Of course, Castle. Who else would want to take Rossi out? From what I've heard from my old pals in the OCU, the Rossi and the Maleno had a small turf disagreement going on about Maleno selling drugs in Rossi territory." Ryan said.

"That sounds like motive to me." Castle looked at Beckett, who nodded.

"Ok guys, let's head back and set up the murder board. Esposito, you and Ryan check the video from the front camera and then go to OCU, and try to get as much information about the situation with Maleno family. Me and Castle will see you back at the precinct." Beckett nodded to Castle and they headed back.

Beckett and Castle had just exited the elevators when Captain Gates called out from the door to her office, "Beckett!"

"Go wait in the bull pen, Castle." Beckett told Castle and walked over to Gates' office. She saw that there were two people already inside. A fiftyish man with grey-golden hair, sitting in a chair in front of Gates' desk and a tall dark-haired man, probably thirty five-thirty six, standing near the window, looking outside. Both turned to look at her as she entered with Gates.

"This is Special Agent Artemis Vicco," Gates gestured to the older man, "and Special Agent Robert Lee, of the FBI."

Already? That was fast. I wasn't expecting them until the evening. Kate thought.

Both men nodded to her and she nodded back.

"They are here because of the Rossi case." Gates added, unnecessarily, as if the FBI would be here for any other reason.

The tall man, Special Agent Lee, spoke, "I was just saying that the Bureau should take point on this one."

"And I was saying, not gonna happen." Gates cut him short. "This is NYPD's case. We appreciate the bureau stepping up to help, but this is our case and my people will handle it."

"We have been following Vincent Rossi for some time now. We have important information and can act on it without wasting time to brief everyone." S.A Lee countered, his face donning a hard mask.

Gates scoffed and said, "Our own OCU has data on the Rossi, and Detective Beckett has the highest closure rate in the city, including the FBI."

Beckett sighed as she thought, And so, it begins..

Castle had been waiting in the bull pen and had jotted down a few ideas for a plot involving warring Mafia families. He could still hear Gates' voice as she and the FBI agents tried to establish the hierarchy of the two teams in the case. It finally came to an end without either side giving an inch, but they decided to start working the case. Beckett came out, talking to an old man, followed by a tall man who was talking to Gates.

Becket reached the bull pen and turned to the tall man.

"This is our work area. There is a briefing room that you guys can set up in." Then she held her hand out towards Castle and said, " This is-"

"Richard Castle." S.A Lee cut in as his eyes widened.

"Um- yeah." Beckett said lamely.

Castle looked at the man interestedly. He knew that look. It was the look he saw often at book signings and book releases. The man was a fan. Castle smiled inwardly as he put on his best book signing face and nodded.

"Guilty as charged." He said rakishly. " And you are?"

The man sputtered something. Richard asked politely, " I'm sorry I didn't quite catch that. What did you say?"

"Robert Lee, Mr. Castle." S.A Lee held out his hand, gushing. "I'm a huge fan of your work. I was crestfallen when you killed off Derrick Storm. But Nikki Heat is even better."

Castle grinned as Beckett and Gates looked on, one amused and the other amazed.

"Well, I'm glad you like my work. If you like Nikki heat, I'm sure you would like to know that Detective Beckett here is my inspiration for the her." He nodded towards Kate who suddenly started to go from amused to irritated.

Great. Now he is going to think I'm slutty like Nikki Heat.

"Detective Beckett?" S.A Lee turned to the woman and looked at her with awe. "I had read your dedication, but I didn't put two and two together." He then said, rather than ask, "KB. Katherine Beckett. Of course. How could I not remember? Agent Shaw told me that she had met you. Is it true that the Special Agent Walle in 'Summer Heat' is based on her?"

"Why, Yes." Castle said to the man and watched as his eyes shined with excitement.

"In fact, you're giving me a good idea for a character I'm trying to think for my next book. I think I'm going to call it 'Mafia Heat'." Castle grinned.

If it was possible, S.A Lee's eyes would have widened further. He tried to process this information as Castle continued, painting a pretty picture of his new possible character.

"Tall, dark but kind. Called in from the FBI to work with Nikki Heat on the string of Mafia murders that are taking place." Beckett glared at Castle, thinking about what the man was trying to do. It became clear as Castle spoke next.

"Initially there was friction between the two, but for the sake of justice, he allows Nikki to take lead, surprised by the ferocity she showed to bring justice to the people who lost their loved ones to the ruthless Mafia. Of course, later he experiences the same ferocity when they have hot passionate se-"

"CASTLE!"

Kate was glaring at him mortified. Beside her was an equally red, but still ecstatic, S.A Lee.

"What?" Castle gave her an innocent look.

"Ahem- I'm flattered, Mr. Castle, but I'm married and my wife would kill me if the character you base on me has- you know- with Nikki Heat. She is also a big fan, but I doubt she will see the fiction apart from reality, especially now that we will be working together." Lee said a little abashedly, avoiding looking at Beckett.

"Oh." Castle mused. "Fine, we can cut the steamy scenes, but I'll keep him giving lead to Nikki. It makes him look good. To think that he would be willing to lay aside his ego to bring justice to the victims, that's the stuff heroes are made of." Castle said smiling. Beckett resisted the urge to slap Castle silly.

"Ah yes, of course." S.A Lee agreed. He then looked at Gates and said, " Perhaps the NYPD can take point this time, seeing as an exceptional Detective will be in charge."

He nodded to his partner, " This is Special Agent Artemis Vicco." The older man nodded to Castle, his face expressionless. S.A Lee shrugged to Castle, "Don't worry, he is like that with everyone. He is a man of few words, but he is the best on Mob related cases."

"I used to be Interpol. Worked in the Organized crime task force." S.A Vicco spoke for the first time. He had a low, firm voice. He turned to S.A Lee. "Should I have the gear set up here?"

"Yes, please." His partner nodded. He turned to Beckett, "Is the crime scene intact?"

Beckett shook her head, "I'm afraid not. We removed the bodies, but left everything else sealed. Our M.E will call us as soon as she finds something."

Lee nodded. "We'll be ready in half an hour to brief everyone. Call in your team."

Beckett nodded as she moved away to call Ryan and Esposito. She told them that they didn't need to go to OCU anymore and they should return as soon as possible.

"Beckett, a word." Gates called as Beckett moved to her white board.

"Yes, sir?"

"This is an important case. Close it nice and good and this will become a good springboard for our careers . This might be the one that brings you in consideration for Lieutenant." Gates looked at her pointedly.

"I understand, sir. We'll do our best." Kate said, hiding a smile. She had known that Gates would look at this case to fuel her own political ambitions. Well, at least she isn't going to claim it all for herself, if she is willing to share it with me. Gates nodded and walked off.

"What was that about?" Castle asked Beckett.

"Just like I told you Castle, Gates is looking for a gold star on her record. She told me she'd recommend me for Lieutenant if we close this one."

"Ooh Lieutenant Beckett. Sounds nice." Castle grinned.

"Yeah, the pay bump will be nice, seeing that I do half of the Lt.'s duties already." Kate sat down at her seat.

"You do? How come?" Rick asked, curious.

"We had a Lt. up to four months before you came, Castle. Do you remember the big debate on cutting back on non-necessary posts in government offices?" Beckett asked the writer.

"Yeah?"

"Well after Lt. Saunders retired, Montgomery was asked if he needed a Lieutenant. He discussed this with us and we decided that we didn't. So, Captain and I divided the work between us." Kate turned in her chair to pick up the files and place them in her drawer, getting ready for all the new paperwork the case was going to bring.

"But, if you make Lieutenant, wouldn't you have to leave the precinct? But I like it here." Castle said like a boy being sent to a boarding school against his wishes. Beckett smiled and said, "Well, you could always get the Mayor to recreate the position here in the precinct."

Castle brightened up at that. "Hey! Not a bad idea. Let me call him."

"Sit down Castle, all of this hasn't happened yet. Even if Gates does recommend me, there are many other distinguished officers with seniority."

"But if I drop a word-"

"NO, Castle." Kate looked Castle in the eyes. "I won't have you using your contacts to give me an unfair advantage over others."

"Fine. It was just a thought." Castle raised his hands in surrender.

They sat discussing for a while until Ryan and Esposito arrived. Kate took them to the FBI team to make introductions.

After the introductions were complete, Beckett asked Ryan.

"So, any luck on the video?"

"No. The front camera along with the cameras leading to the suite were 'malfunctioning'." Ryan air quoted.

"What about the Key?"

"Easily duplicated if you know what you're doing and can get your hands on an original." Esposito said, glancing at his notebook. "And according to the shift manager, a maid couldn't find her key yesterday but later found it in her bag. And dig this, the cameras in the staff area were malfunctioning yesterday as well."

S.A Lee nodded. "The hotel uses wireless cameras that are connected with a WPA-sk protected network. Difficult, but not impossible to break into. Also, the guy could have been just jamming the wireless spectrum." He turned to Esposito, "Ask the staff if there was trouble with cell phone reception yesterday in the hotel."

Esposito nodded and moved away to make a phone call.

"What about Benito Rossi? When do we head out to meet him?" Ryan asked.

S.A Lee shook his head. "We talked to the Rossi household. The old man has been sedated after he had a small heart attack on hearing about is son. The doctor said he'll let us know when we can talk to him."

"Is this a Data Matrix analyzer?"

Everybody turned to see Castle looking at the large screen that the FBI team had set up. Beckett glared at Castle as he asked, "What?"

"Ahem, actually yes, Mr. Castle. It helps us find relevant information that we might miss otherwise. How did you know?" S.A Lee said surprised.

"Agent Shaw had one of these as well." Castle grinned.

"Oh, you'll find that this one is better, Mr. Castle." Lee pointed to the wires leading to an open suitcase that had a kind odd small antenna thingy. "We are directly connected to the FBI's central database, and hence this set up is much faster."

"Oooh nice. " Castle said as he took out his notebook and started scribbling.

Beckett smiled at her partner's excitement.

"So, anyways." She said. "Let's begin."

In Italy, in its southern countryside, stood a big castle like mansion. The mansion was very impressive, fit to be the home of a king. There were many armed men in suits patrolling the grounds. All of them stopped to salute or bow to a young man making his way inside. He responded good naturedly to all greetings. He slowly moved inside the castle and went to the second floor where his friend's office was situated. He nodded to the five men sitting in the small waiting room outside the main office. He smiled at the scene. It was not like the man inside needed any guards, but his subordinate didn't listen to his meek declarations that guards were not necessary. The self-proclaimed right hand man had bulldozed over this and had argued that he was the Jyudaime, and the boss, it was a custom that he should have the best guards. His friend had finally agreed.

He pushed open the doors to walk inside. Immediately he noticed that something was amiss. His usually happy and smiling friend had a sad and angry expression on his face. The silver haired man also didn't comment on his arrival, no insults for being late. His eyes narrowed as he noticed that all the other guardians were present as well, including the ex-disciplinary in charge and the ex-vindice convict.

"What happened, Tsuna?" he asked.

"Our emissary to the Rossi family in the US, Carlo Messi, was killed." Gokudera said quietly.

"That nice guy? I didn't know he was going on missions."

"It was his first." Tsuna said softly.

"The Rossi killed him? Are they mad? Weren't they the ones who wanted to join the Alliance?" Yamamoto asked, looking around.

"We do not know as of yet. That is why I have called you." Tsuna looked at his friend. " I want you to go to the United States and investigate." Tsuna leaned back into his chair. He looked very scary as he turned to look down at the small group photograph of his subordinates in the file Gokudera had given him. He had taken one with different groups that worked in the castle until he had covered all of them when he had officially taken control from Nono. He sat in the middle with Nono, flanked by his guardians on his side and his predecessor's on the other side. All his men standing behind them. His glance fell on an ordinary looking man smiling in the third row. Now this man was dead, killed.

"Find out who killed him and why." Tsuna ordered his rain guardian.

"And after that?" Yamamoto answered. All of them had been forced to grow up from the naïve children they were after five Families in the council had formed an alliance and tried to take down the Mafia council a week after Tsuna had taken over. It had been a bloody war, where they had lost many of their own. Tsuna had held back from taking lives until the enemy had attacked a safe house of his father's and CEDEF had fallen, with the enemy taking the girls hostage. Tsuna had flown to the place on hearing the news. By the time Yamamoto and the other guardians had reached the site, Tsuna had crushed his heart in order to save them. They had arrived to witness a scene that broke their hearts. Amongst hundreds of bodies, Tsuna kneeling and wailing to the heavens, covered in blood, in Kyoko's arms as she tried to console him.

That day, Tsuna had added his own sins to the Trial of the Vongola Bosses. In the end, only Basil, Oregano and Lal mirch had managed to survive. Tsuna's father had lost an eye, but survived. Even the Varia had been silent at the scene.

"The Varia will deal with them." Tsuna said shortly.

Yamamoto nodded and said smiling, "I'll need someone else with me. I'll get tired searching such a large place alone. I'll get bored."

This brought a small smile to Tsuna's face. He sighed, trust Yamamoto to lighten up the situation. Just because he was sad didn't mean he should wallow in it. He turned to Yamamoto with a glint in his eyes as he said, "Fine. Hibari-san will go with you."

The Japanese Skylark glared at the brunette and he hurriedly added, "Hibari-san doesn't have to go if he doesn't want to."

Yamamoto protested.

Tsuna looked at his friend and knew he was cornered. He never could refuse his friends. "Fine, You can take Chrome."

Again the Japanese Skylark glared at his 'Boss'. If he thought he was sending Chrome with the herbivore alone, he was mistaken.

"Perhaps then I will go with my darling Chrome, Fu fu fu." Mukuro said as Hibari glared at him too. Mukuro just laughed at the Cloud guardian's anger.

"No. I will go with her." Hibari said, leaving no room for argument.

He turned to look at Yamamoto, "If you get in my way, I'll bite you to death." He nodded to chrome to follow him.

"Goodbye, boss." Chrome bowed to Tsuna and followed Hibari.

Yamamoto smiled and said, "I wonder why he doesn't just say it out loud. Everyone knows."

"Because it isn't Hibari-san's style." Tsuna said. "Besides, Chrome understands."

Yamamoto gave Tsuna a shrewd look, "You knew that if you sent Chrome, Hibari would go too."

Tsuna smiled and leaned back into his chair as he said, "I don't know what you're talking about."

Yamamoto continued to look at Tsuna, his lips twitching. Finally Tsuna shrugged and said.

" Hibari-san is the best in information gathering. But I can't send him alone as he would create incidents with the locals."

"So use me as a scapegoat?" Yamamoto smirked. "Well anyways, I'm off as well. I'm taking the jet."

"Yamamoto."

Yamamoto turned to look Tsuna had gone serious again.

"Please try hard. For Carlo-kun."

Yamamoto nodded and he waved his hand as he left.

There we go...

Anyways, updates might be a bit random. This isn't my primary focus right now. I'm trying to get my brain to start on Twist Of Fate again.

If you liked it, drop me a line. :-D