AN: Thanks to everyone who reviewed chapter one. I hope you like the ending.

Sherlock and Beckett had worked on, heedless of the hour or the need for food and drink. After a long time though; they were both out of available evidence, and were now scribbling conjecture on the Murder Board. Theories, possibilities... And when they were done, they each took a look at the others conclusions, and began editing. More than an hour had passed before Beckett had noticed her coffee had gone cold. She glanced over at Sherlock. "You need to take a break?"

"No." Sherlock said shortly. "You?"

Beckett shrugged. "Isn't the first time I've pulled an all-nighter."

Sherlock nodded, silent for a moment. "What about you John?" There was no answer and Sherlock turned to look. "John?"

"Dr Watson left the Precinct with Castle over an hour ago." Beckett reported; unsurprised that he hadn't noticed.

Sherlock looked around; surprised to hear it. "Oh. Castle's your partner? He doesn't seem like your brand."

"My brand?"

"He goes home to play laser-tag with his daughter, while you keep working." Sherlock pointed out. "That to me seems incomprehensible. How do you stand him?"

Beckett was silent a moment. "I guess... In a way, I envy him."

"You are his superior; and he is a child." Sherlock said directly. "What could you envy?"

"His childlike nature." Beckett explained. "I spend all day, every day; thinking about murders and death. After a while, you see everyone as either a victim, or a perp. Castle can put it down when the case is over. I envy him that."

Sherlock looked away from the board for the first time. "I... admit, that at times I wonder if maybe there's something lacking. Now and then... I'm an aberration; not like anyone else. My office is my home; I never put it down. When I don't have a decent case, I have a tendency to..."

"Go bat-crazy?" Beckett guessed.

"Suffer in boredom." Sherlock countered.

When they arrived back at the Precinct, Castle handed Beckett a large espresso, and Watson handed Sherlock a nicotine patch. Both detectives took the offerings without comment, long used to it.

"Sherlock was right. It's obviously not Moriarty." Beckett said as soon as they settled. "So how's our copycat picking the victims?"

"Both are connected to money, both have dirty secrets." Sherlock said. "What we need, is a way to connect the two cases. The connection will be our killer"

Ryan came up behind them at that moment. "We tracked Klass. His Tuesday was routine; leave home, go to the office, a standing squash game then a phone conference from his car. He usually goes to the hotel after that, but his wife called to tell him Joey was missing again."

"If this guy is that good; good enough to invoke Moriarty..." Castle began. "Then maybe he picked people that had no connections? It would eat up our time."

"No." Sherlock didn't hesitate. "When Moriarty plays a game, he has a large base of possible victims to choose from; all unrelated, all suited for his purposes. Our Copycat doesn't have those resources. He had to have had access to these dirty secrets. He had to know about Klass's affairs, or that Doyle's cancer didn't exist; and he had to do it alone." He tapped the board. "Somehow, these people are connected."

"The Gambits, or the hostages?" Castle asked.

Sherlock rolled his eyes impatiently. "The hostages are nothing." He said irritably, ignoring the way Beckett twitched. "Our killer had to know the answers to each mystery he gave us; so he must have inside knowledge." He waved at the list of rescued hostages. "A hostage he can take at random off the street."

"Not at random." Beckett said. "He had to pick them, or hire people to pick them. Ryan, run the hostages. Where they were snatched, who saw it happen, check for surveillance footage; you know the drill."

"On it." Ryan said immediately and took off.

"Esposito, you find connections between our cases. The wife, the mistresses, the reporter, the clinic... Anything. Keep Lestrade informed too. Maybe our killer was planning this before he came to the States."

Esposito nodded and turned to his task also...

And the Pink Phone Rang.

Beckett and Sherlock gathered around it immediately. The photo was of a vacant lot.

"I can see buildings behind it." Sherlock said immediately.

"Upper west side architecture." Beckett agreed. "I'll send it out."

"There's been no call." Castle said suddenly. "Usually we hear from the hostage before we get the clue."

Sherlock nodded. "Not the third time. Our copycat is following that pattern." He looked over at Ryan. "You always seem to come over with relevant information whenever someone asks a question out loud; where are we on tracking down London Police in New York?"

Ryan concealed his irritation thinly. "It's going slowly. They don't have to mark themselves down as Police Officers when they come to the states; and there's no way to know if they even came straight here. They could have landed in Canada and driven the rest of the way."

Watson raised a hand. "I'll Lestrade, see if the can track it down from his end."

Ryan and Esposito left the Precinct almost immediately after they got the image; not knowing where to go.

Beckett and Castle stopped to collect Laine, but Sherlock didn't want to wait. Beckett made a squad car available to him. Gates had approved of the tactic, splitting up their investigative team; increasing their chances of someone finding the location show in the photo before the clock ran out.

The three vehicles full of investigators scoured the city; specifically the West End. None of them found it, but eventually a Beat Cop noticed the buildings they were looking for; and after over an hour had passed; they got the call. Their next puzzle was an empty hole in an expensive part of town; forgotten by the locals who made it their business to ignore other people's business.

"You detecting a theme here?" Watson asked. "All the places we get sent to involve money, or neighbourhoods with wealth, but are sitting unused."

Sherlock didn't answer. "Data. Everything is still data at this point. Did Lestrade give you anything?"

"He's running it down; but in a lot of ways he's hitting the same problems the NYPD have. Roughly ten percent of the manpower is on leave at any given time; several dozen have retired or stood down since The Great Game. When a cop leaves the London Force, or the Yard; they don't have to check in when they leave the country."

"Process of elimination Watson." Sherlock said simply. "A detective does not notice important facts; a detective notices all facts and works to eliminate the unimportant ones."

Watson nodded. "Speaking of what a detective does; what do you think of Beckett?"

"She's almost a Lestrade." Sherlock said. "It's possible she might prove herself better than him in time; but I doubt we'll be here that long... She reminds me a little of The Woman."

Watson reacted. It was the first time Sherlock had mentioned Irene Adler voluntarily. "How so?"

"She uses every advantage to get what she wants." Sherlock didn't look at Watson. "Don't ask her out. She's in love with Richard Castle."

"Don't need to be a detective for that one." Watson snorted. "I have to say; it's still surprising to me that you're... invested." He observed. "We've been able to eliminate Moriarty as a suspect."

"Not all the cases that interest me involve Moriarty." Sherlock commented, his eyes a million miles away. "What do you think of their team?"

"They're cops." Watson said easily. "Beckett's a lot like you, only a little less... you. Ryan and Esposito are loyal to her as a pack of guard dogs. And then there's Castle."

"You've wanted to meet him a while." Sherlock observed. "You get his autograph yet?"

Watson shook his head. "Didn't seem like the time. Maybe after we catch the killer. Still; if he's managed to work his way into the NYPD's good graces for this long he must be worth it." He glanced over. "You've never asked me for an opinion of other people before... Something interests you about these ones?"

"A few days ago; I thought this might be Moriarty. For months now..." Sherlock hesitated. "The Great Game was his personal challenge to me. When I heard someone had restarted it over here..."

Watson felt his jaw drop open at the hinges. "You were jealous? You were! You were jealous that your great and worthy opponent might have found someone else to play with! Is that why we came over here so fast? To see who else might be worthy of being Moriarty's mortal enemy?"

Sherlock hesitated. "We're here."

Watson looked back out the window to see their squad car arrived at the Lot. Ryan and Esposito had already arrived; and a team of K-9's were already making their way around the lot, carefully searching.

By now, the news had spread that Team Beckett was working on a trans-Atlantic caper; and more than a few extra police had joined the case. More than a few of them were peeking at the newcomer; and Sherlock had to admit the extra hands made the early stages more efficient. Small markers were already set all over the place.

"Why the extra police officers?" Watson asked. "Most of these K-9 Detective's aren't from the 12th, at least not in the bullpen..."

Sherlock nodded. "First case I ever officially consulted for Scotland Yard? The London Tube Bombings. I imagine NYPD takes bombings as seriously as The Yard, if not more... especially when hostages are involved."

Watson gave the comment a single nod. "You don't have to tell me Sherlock; I was stationed in Afghanistan."

Ryan and Esposito waved the Consulting Detective over to them. Watson noticed Beckett and Castle pulling up with Laine in a civilian car. As they approached the two waiting NYPD Detectives; they saw that a small skeleton had been dug up; half excavated out of the hard caked dirt of the lot.

"Why is this real estate empty?" Sherlock asked immediately as he approached; eyes on the bones. "Even in this economy, you'd think someone would make use of a location like this."

"The lot was bought nine years ago by Walter Newbern. Real Estate Money; he could afford it." Ryan reported, looking at his phone.

"Real estate money." Watson put in as Castle and Beckett came into range; Laine dropping instantly to her knees to check the small skeleton. "He's a developer; so why hasn't he... developed?"

Ryan shook his head. "Unknown. The lot was cheap then, and Newbern got it for a song, but prices rebounded a few years later, and he refused to let the place get developed."

"Laine?" Beckett looked to her friend.

"Body is a juvenile male; maybe seventeen, maybe a little older. Cause of death... hard to tell, but it wasn't anything involving brute force or bullets. I'd say the body has been here... fifteen years?"

"Fifteen years ago; but the lot was bought nine years ago." Beckett said. "So why didn't the buy notice a corpse on his new investment?"

"Because he's the one that hid the body here." Castle theorized. "He bought the lot to hide the body."

"Who owned the lot before Newbern bought it?" Sherlock asked quickly; and Castle handed over his smart phone before being asked.

Ryan checked his notes. "The name on the contract said it belonged to the bank for six months... Before that it was owned by someone named Larkin Whitsett."

Watson piped up as Sherlock went to work on Castle's phone. "Seems like an expensive way to hide a body in New York; especially for this long. Could be a coincidence." He knelt down and took a look at the corpse himself. "No shattered bones; no bullet holes I can see... The kid could have choked on a lollipop for all we know."

"Hard to tell till we know how the victim got here." Beckett waved him off.

"Can't know that until we know who the body is." Laine said, making a quick examination. "No chance at getting prints after this long; but it looks like he's had dental work done. I'll make some molds and find out who-"

"We've got a mad bomber on the loose, and four hours to save a hostage; we can't wait for dental records to come back." Beckett shook her head.

"Well it can't be helped." Laine insisted. "It's a skeleton; we'll never identify him in time."

"His name is Hugh Greve." Sherlock said calmly. "The owner of the lot isn't the one who killed this boy, because if he was, he would have fifteen years to move the bones." He glanced around. "But he wouldn't allow building on the site, so he must have known it was here somewhere. Our killer is Newbern"

"And how do you know that?" Castle commented with wry amusement.

"The lot was bought six years after the body was left here." Sherlock explained. "Fifteen years ago; Hugh Greve was in Prep School, and according to the school annual; he was in school with both Larkin Whitsett and Walter Newbern. Greve was declared missing; and never found. So the body of a boy that never got found was on Newbern's property the whole time; and when he lost it; it was immediately bought by Whitsett. The two of them are covering up the death of their missing classmate. If they didn't do it, then they know who did. If Newbern did it, he could have moved the body before he sold it; so he's an accomplice."

"God, I hate that I'm becoming a fan of yours." Castle commented.

Beckett looked to her team. "Ryan, Esposito: Find a connection between these bones and our previous puzzles." She checked her watch. "Three hours, twenty minutes."

Another hour and ten minutes passed, with no connection becoming obvious.

"No school connections; no phone matches, no family connections; no friends in common we can track down..." Beckett rubbed her eyes. "I need coffee." She left the murder board without another word and went toward the break room quickly.

Castle followed her.

"You want one?" Beckett asked without even turning back to look at him.

"Thanks. I could stick around and watch Sherlock burn holes in the murder board with his eyes, or I could follow you in here and have espresso. I'm amazed it took me a whole two seconds to decide."

Beckett smirked and worked the controls of the espresso machine quickly. "So. Alexis?"

Castle sighed. "Sherlock was right. A sentence that is rapidly losing its novelty." He glanced over his shoulder to make sure they were alone. "Mother says Alexis has been acting secretively; hiding her phone when she gets text messages; humming to herself. Alexis is seeing someone... and it's the first time it's happened without her telling me about it."

"Castle; she's a teenage girl." Beckett said soothingly. "I've met Alexis, if this is the most Teenage thing she's ever done; then you're fine."

"But if she's hiding him from her father; then maybe Sherlock's right about him being trouble."

"I hope for Alexis sake that he is." Beckett smiled. "If he's trouble you've got three armed cops on speed dial. If he's just a teenage boy she likes; he'll be harder to remove and you've got a real problem."

Castle let out a low growl, and Beckett grinned at him.

He noticed. "What?"

"You." She chuckled. "You and Alexis are all laser-tag, and zombie movies... the second a teenage boy gets involved, you go nuclear."

"Means she's growing up." Castle said sullenly.

"Yeah, but you get sad when you get a reminder of that." Beckett pointed out. "You only get furious when there's a risk of her having a man in her life that's not you."

Beckett ended the conversation with that thought and the two of them returned to the bullpen with their coffee; noticing that everyone was looking pointedly down at their files or their desks. Esposito was over near the murder board; with violence in his face. Watson looked embarrassed; Sherlock was almost smirking; and Beckett could swear she caught a hint of Laine's curves heading for the elevator at a quick march.

"What happened?" She asked.

Ryan leaned over and jerked a thumb at Sherlock. "Laine brought up her autopsy results; Freak-Boy took one look at her and Esposito together; decided to spread a little sunshine around..."

"Say no more." Beckett took the autopsy results and skimmed them. "Poison?"

"Poison or asphyxiation." Esposito corrected. "There were rag fibres between the skeleton's teeth. According to the medical records, Greve had a congenital heart defect; which caused his body to react badly to being gagged."

"It's called Lactic Acidosis." Watson put in. "The body starts burning lactic acid because of the asphyxiation. That could have been caused accidentally by the heart condition; or there could have been poison on the rag."

"So it could have been an accidental death, or it could have been pre-meditated murder." Kate let out a breath through her teeth. "Either way; we can't do anything until we know who put the rag in his mouth. Tell me we have something."

"Well, Sherlock was right." Ryan said. "That lot where we found the skeleton? The name on the deed was Larkin Whitsett, but he's got zero money. Employment files say he's been unemployed since he left prep school."

"Living on family money?" Castle guessed.

"No trust fund we could find."

"Then where was he getting the money for real estate?" Beckett asked the question. "And if the lot's been left vacant and empty for six years; why hasn't he done anything with it?"

"Detective." Captain Gates called from the door to her Office. "A word with you?"

Beckett came into the Captain's office and shut the door behind her. "Sir?"

"The State Department wanted to know why the 12th was demanding the travel plans of several Scotland Yard Detectives." Gates said. "And of course that outed the mad bomber angle."

Beckett winced. "Is anyone going to release it?"

"I'm frankly amazed it hasn't leaked out already. At this point; we're trying to convince the State Department that this is not an act of foreign terrorism. Except that it is. So we're trying to convince the White House that this is some nut getting his kicks and not an attack on American Interests." Gate pointed at her phone. "Have you ever received an unexpected call from the Secretary of State, Detective Beckett?"

Beat.

"I can honestly say that I have not." Beckett conceded slowly.

"They don't want to start a panic, so they've given us a chance to fix the problem before the decide to federalize the NYPD." Gates summed up. "We've got 24 hours to catch this sonofabitch, before they bring the hammer down and tell the whole world. Understood?"

"Understood." Beckett said promptly, and headed back out into the bullpen.

"Our job gets harder in 24 hours." Beckett reported to the team. "What did I miss?"

"Mr Castle was just showing us his top investigative tool..." Sherlock reported sardonically. "Facebook."

Beckett looked to her partner, who held up his hands. "The lot where we found the skeleton is owned Larkin Whitsett, so I looked him up. He's one of those idiots who keeps posting drunken photos of himself and whatever girl he's sleeping with online."

"Right, idiots." Esposito needled. "And... how many people re-tweeted the shot of you and Meredith in Atlantic City?"

"At least a thousand." Castle said without missing a beat. "But my point is: that kind of hedonistic lifestyle isn't cheap. The prep School website is light on details; so he's not successful, and he's not from money or power. If he doesn't have a job, and he doesn't have a trust fund... Then where's he getting the cash?"

Beckett's eyes flashed. "Good question. What say we go ask him?"

"No time. He's in Vegas right now."

"Waste of time anyway." Sherlock dismissed instantly. "The man we want to talk to is Walter Newbern."

"Why him?"

"If Whitsett bought a lot of property he couldn't afford, then he's not our killer... but he knows who is." Sherlock said simply. "The victim, Whitsett and Newbern all know each other from school. One is dead, one is rich, and the other is keeping the connection between those two facts a secret."

"I don't know Sherlock, that's a reach." Watson said. "Just because they were all at the same school together doesn't mean that Newbern is supporting..."

"No, but Newbern has money enough that he's probably got more than anyone knows about. He'd know how to keep the accounts hidden." Sherlock cut him off. "You buy empty property to develop it into something; it's an investment. Whitsett kept it the way it was for years and years."

Castle piped up. "Could we run Newbern's financials, see if he's making payments out to Whitsett?"

Beckett shook her head. "He'd be able to cover up a paper trail... And we'd never get a warrant to search his place for evidence." She glanced at the taller man. "Holmes, how sure are you?"

He just looked at her. It was a waste of a question and they both knew it.

Beckett bit her lip. "Then we try Plan B."

"What's Plan B?" Watson asked.

"We're gonna cheat." Castle said brightly.

Castle, Beckett, Sherlock and Watson all strolled into the plush lobby of Newbern's office building, ready to pounce. The receptionist seemed surprised to see four of them coming in at a quick march; and downright terrified when she got a look at Beckett's badge. The four of them went straight past the front desk and headed straight for the elevator.

Once the doors closed; Beckett turned to the three men. "Now, is everyone clear on the plan?"

"We're basically going to go in there and ask him confess." Watson quipped.

"We'll open with the photographs of the body; then we'll ask him some polite obliging questions; then Sherlock will start pointing out inconsistencies." Castle said eagerly. "This will put him on edge, so that Beckett and I will have leverage to play good cop; then we'll casually mention that we know about Whitsett and see if that shakes something out of him. If not enough for us to nail him; then maybe enough that we can get a warrant."

"Isn't that what I said?" Watson asked in slight confusion.

"Yeah, but..." Castle scratched the back of his neck. "I thought that-"

"You thought you'd use more words." Watson nodded. "Trust me, I'm used to it."

Sherlock almost smirked. "Remember, this man is an executive, used to concealing his real thoughts. He's probably known about this death for at least fifteen years and has been taking steps to cover it up. A man with as much to lose as Newbern has will no doubt have spent considerable thought over the years preparing his reactions, his alibi... He's been waiting for this conversation a long time. He will be hard to break."

The elevator dinged, and the doors opened for the four of them; bringing an end to the discussion.

Walter Newbern was waiting for them as they came into his office. "Good morning." He said with a slightly guarded tone. "The lobby rang to say that had unexpected visitors; but I wasn't expecting so many. And... who are you all?" Newbern asked.

Beckett held up her badge. "Detective Kate Beckett, NYPD."

"Sherlock Holmes, Consulting Detective."

"Doctor John Watson, Fifth Northumberland Fusiliers."

"Um... Richard Castle, outside agitator."

Newbern took that in and just looked confused, but still cooperative and polite. "An interesting company to be sure... And how can I be of service to you all today?"

Beckett took out a school photo of Hugh Greve and held it up. In the same moment, Sherlock drew a crime scene photo of the skeleton; and held it out beside the first. The two images together were presented without a word.

Newbern saw the photos... and collapsed. His knees gave out instantly; and he slid to the floor against the side of his big oak desk. His face dropped into his hands and his eyes filled with huge tears. A moment later he was sobbing hysterically.

The four Investigators just looked down at him, a little surprised at how quickly the wealthy man had fallen apart.

"It's my fault!" Newbern bawled. "I #sob# am #sob# so #sob# SORRY!"

Watson glanced at Sherlock, who actually seemed slightly embarrassed, one eyebrow raised in awkward discomfort.

"Plan B." Castle observed to Watson. "Easier than I thought."

Beckett went over to the office wetbar and poured the man a drink. Castle and Watson did their level best to lead him over to the couch that looked over the city.

"Tell us what happened." Beckett said firmly; like a schoolteacher with a crying pupil.

"It was only meant as a joke." Newbern sniffed. "Fifteen years ago; it was Hugh's birthday... We planned to pull a birthday kidnapping; snatch him away; take him out to a bar and get loaded; stick him back in the trunk, go out to a club or something... But when we opened the trunk; he was dead."

Beckett nodded. "And for the record, when you say 'we' you mean yourself and..."

"Larkin Whitsett." Newbern sobbed the name out wretchedly. "The gag in his mouth was a rag we had... It was just lying around; but it must have had paint thinner on it or something because..." He rubbed his face. "Hugh was my friend. It was his surprise birthday party and..."

"Why didn't you report it?" Beckett pushed.

"I was scared! I was the one that got the rag; I was the one that put it in his mouth. We were playing pretend, and I was the one that..." Newbern slugged the drink back hard. "Larkin told me not to worry. He said that he would take care of everything. He said to go home and put it out of my mind; and nobody would know."

"And then six years later, he bought that lot off you." Sherlock finished. "And a promise to help turned into blackmail."

"Six years passed, and Larkin came to me, said the lot was still..." Newbern sank his head into his hands. "He said he'd hidden the body; and never gone back for it. He promised he'd protect me. He said, all I had to do was..."

"Be his meal ticket for life." Castle finished. "You keep him in booze and corn chips; he keeps his mouth shut."

"He wanted a pay-off. I gave it to him; but he came back a week later, and he said..." Newbern sniffed. "He said that it wasn't enough. He... he said he had cameras in the Lot. He said if I went sniffing around, looking for the body; he'd have a nice clean photo of me standing over the bones; and I'd be finished."

"And he could never sell or develop the lot himself because if he did; the body would be found his own involvement would come out." Sherlock finished.

"And if he ever went back and moved the body somewhere himself; you'd be able to put it behind you." Castle nodded. "But as long as you kept paying him off; he could go out and party forever... That's why the body was still there and the lot left empty. if he ever disposed of it properly; his income disappeared."

"It wasn't worth it." Newbern said weakly. "The money... was nothing I make that back in interest on my trust fund every week. But I've been waking up in a sweat every night for fifteen years." He broke down sobbing again, clutching at the scotch in his hand like a safety blanket.

"The joke was on you." Castle said. "We found Greve's body. The Autopsy said it was a reaction to the cloth. He had a heart condition; so when he was asphyxiated; his lungs reacted differently. It was an accident."

Newbern took that in and turned to the Mantelpiece. His red eyes focused on a large framed photograph; done in black and white. "Fifteen years..." Newbern whispered. "I never thought... I thought I'd killed one of my best friends. I was young and terrified; and... after a while I couldn't bear to tell the truth." He took the photo off the Mantle and hugged it to his chest. "God, I want it to be over."

Watson was standing closest to Newbern and he saw the photo. His face changed and he quickly reached out for it. "Here. The one of the left... Is that Whitsett?"

Newbern nodded sadly. "Yeah, that's him. He'd just made Varsity."

Watson held out the photo to the others. "Varsity. He's got a big number Four on his jacket."

"There's our magic number." Castle nodded. "The one blackmailing his way into a cushy lifestyle."

"Well, he won't be living the good life for long." Beckett retorted, and pulled out her handcuffs. "Newbern, you're under arrest for conspiracy to obstruct justice, involuntary manslaughter, bribery and whatever else I can think of between here and the Precinct."

The Pink Phone Rang as they re-entered the Precinct. Sherlock; who somehow managed to hold onto the Pink Phone all the time now; answered it. "The fourth key." He said before there was any response from the other line.

"Are you sure?" The hostage called back. The voice sounded very… young.

Beckett and Castle froze at the sound of the voice. "It's a child." Castle blurted. "Younger than Alexis…"

"I am sure." Sherlock said seriously. "The fourth Key."

There was a moment of silence. Beckett saw the entire bullpen watching them out of the corner of their eyes.

"Hello?" The child said a moment later. "The… the countdown switched off."

Everyone let out a breath they hadn't realized they were holding; and the Precinct burst into a round of spontaneous applause. Money changed hands; yet again; and the hostage spoke up. "He said to tell you 'congratulations on round one.'" The child's voice tripped over the larger words as she relayed the message. "He says 'round two tomorrow, because he's calling it a night'."

Beckett took the phone and handed it to Ryan. "Trace the call, find the kid."

"He's 'calling it a night'?" Sherlock repeated in frustration.

"Don't be clingy, Sherlock; it sends the wrong message." Watson told him.

"That's three." Castle said. "How long do we keep playing this game? Sooner or later he'll screw up, or we will and we won't get there in time."

"Ever play Chess, Castle?" Beckett said with a smirk. "There comes a point in the game when you can't figure out how to win; so you pick up the board and throw it across the room."

"You did that too?" Castle grinned.

"Of course not; I've never lost a game of chess in my life." Beckett retorted. "But, when the deck is stacked against you; you only win by ignoring the rules of the game. Our Bomber set the rules to keep us chasing him. We have to flip the rules; and we do that by finding him."

"Which gives you a few hours at least." Gates said from her office. "Go home, see your families; tell them to stay indoors for a while; then say goodbye to your pillows; because if this goes on for one more day; all hell breaks loose." Gates said. "That wasn't a suggestion;' it's an order. The bad guy is sleeping; which means he'll be at his best in the morning. I want my people saying the same." She went back into her office before anyone could respond; effectively ending any chance of argument.

Watson yawned. "Well, since it's an order." He demurred. "Ohh, by the way Sherlock, Mrs Hudson asked us to pick her up some souvenirs when we got a moment." Watson said absently. "So did Molly."

"Must I?" Sherlock sighed.

"Be nice to Molly." Watson said, not for the first time.

"Why?" Sherlock asked.

"If for no other reason; because she has a crush on you." Watson said with severity.

"Poor girl." Castle commented. "Come to think of it, do you guys have a place to sleep?"

Watson nodded. "Lestrade pulled some strings with a hotel in town that looks after Scotland Yard when they're here on assignment; there's a room waiting." He yawned. "Still on London time, but I think I can sleep."

Sherlock was already onto something else. "I don't sleep; John, you know that."

"Which is fine for me; because Lestrade could only get one room for the two of us. Personally I think he was just having a lark." He yawned again. "Good night. I assume you don't want me to wait up for you?"

Sherlock barely registered the comment, and Watson headed out.

Castle started humming the theme of 'The Odd Couple' and Beckett smothered a laugh as they both headed for the elevator. "He keeps insisting he and Sherlock aren't together, but they bicker like a married couple."

"So do we." Beckett retorted.

"Yes, and everyone, from random suspects, to the Newspapers, to FBI agents all assume we're going at it like rabbits." His face relaxed into a lecherous grin. "So frankly; we're just wasting a perfectly good opportunity."

Beckett rolled her eyes. "Good night, Castle."

Castle arrived home and hung up his jacket; surprised to see everyone was still up. Martha was in the kitchen; setting up the coffee machine for the next day; and Alexis was at the counter, hunched avidly over her laptop.

"She's been reading that blog all day." Martha waved at her granddaughter. "She's all over his website too."

Castle made no comment, going over to sit at the kitchen counter beside his daughter. "Hey."

"Hey." She leaned her head back against him for a moment, instead of a hug; never taking her eyes off the screen. "This is him, right?"

She was looking at a news report of a big case that had Scotland Yard baffled. The image was of Sherlock shying away from the cameras in a deerstalker hat. "Yup; that's Sherlock Holmes." Castle confirmed, glancing at her.

"What's he like? Is he amazing?" Alexis asked, a little more seriously that Castle liked.

"Okay, what's going on?" Castle demanded lightly. "You're acting a little... fangirl-ish. And normally, I wouldn't mind that, but the guy is a high level sociopath."

"An incredibly brilliant one." Alexis shot back. "The best scene in all your mystery novels is always the denouement. The sleuth calls all the suspects together and tells them who the killer is and how he figured it out. It's just..."

"Addictive, being close to that much brilliance." Castle quoted Watson.

Alexis nodded. "It's... inspiring."

Castle's face changed. "That's the voice of experience." He said slowly. "You haven't even met Sherlock Holmes, so who's brilliance are you getting addicted to, daughter?"

Alexis' cheeks turned the color of her hair. "I... I've been looking around colleges the last few days; met plenty of brilliant people." She demurred.

Castle just looked at her; feeling a spike go through him. "You know, when he first came into the Precinct, The Consulting Detective sort of... showed off a little. He got an A&E Biography on you from just the smell of that aftershave you gave me."

Alexis' face didn't change, but her fingers stilled on the laptop keyboard. "Really?"

"Really. You've never even met him, and you've been Sherlocked." Castle commented gently. "You know you can always tell me things; right?"

"I know." Alexis smiled up at him. "And you know you can always trust me; right?"

It was warm, it was loving, it was just what Alexis would always say...

So why did it feel like she was running circles around the truth?

Watson woke up as his phone started buzzing. "Hello?"

"It's me."

"Dr Parish?" Watson sat up. "What is it?"

"Tell the 'Consulting-Pain-in-the-Detective' to get his big beak out of my morgue; or I'mnna slap him! And then you!"

"For Science!" Sherlock's voice insisted in the background.

"What's he doing?" Watson groaned.

"He's trying to dissect people in my morgue." Laine complained. "These aren't medical cadavers; these are victims dammit."

"The cases are already solved." Sherlock's voice was raging through the line. "The only thing left is for them to be useful before someone wastes them on burial!"

Watson yawned. "I'm on my way."

Everyone was on call early the next morning. Having a bomber tell that that he kept nine to five hours was unusual to say the least. The entire team came in a few hours early and started hunting again. At some point during the night, Sherlock had procured a smart-phone for himself.

"No evidence from the hostages." Esposito reported. "They were all kept in abandoned places; never got a look at their kidnapper… Laine says they were all knocked out with straight up chloroform; available in a million places. Explosives were construction dynamite; matches a batch that was reported missing over a month ago. The investigation into the missing explosive declared it to be a clerical slip; there was no alert posted."

Watson yawned again. "Well, his focus is on the puzzles; the hostages were only a reason to keep us playing; so it stands to reason he wouldn't have a lot of regard for them."

Castle's phone beeped, and he checked his incoming messages. It was from Alexis. The blog says Dr Watson's a fan. He ask for an autograph yet? – A

Castle texted back. Not Yet. – C

"No prints, no DNA."

"He's not Moriarty, but he's still Scotland Yard." Sherlock observed. "He knows how to avoid forensics."

Alexis reply came back. Take a photo with him, have him put it on Facebook. In fan-world, that's a lot better than an autograph. – A

Castle smirked, and his face froze. A moment later, he was tapping away at his phone quickly.

Sherlock was staring at the Pink Phone in his hand. "It's been seventeen hours. I don't understand what he's waiting for." He growled out.

"Maybe The Game is over?" Esposito suggested. "By now he knows Holmes and Watson are here... He probably wasn't expecting that. The original game went for three rounds; maybe he's just finished playing?"

"Hey." Castle said casually, perched on the edge of Beckett's desk. "I know what the connection is between our puzzles." Everyone looked at him in shock, but he didn't even look up from his phone.

"Well? " Sherlock looked at him fiercely. "What is it?"

Castle grinned at him. "One sec, I just want to have this moment." He mock-shivered. "Ooh, I can see why you enjoy it so much."

Sherlock was not amused. Watson, Beckett, Ryan and Esposito were struggling not to laugh.

"What. Is. It." Sherlock repeated impatiently; his voice dropping a few octaves.

"Just... let me savor it; you've been having all the fun." Castle said, his voice going into a sing-song. "I know something you don't know."

Sherlock's eyes flashed. "Tell me now, and I'll tell you next week's New York Lottery Numbers."

Castle froze. "Really? You can do that? How?"

"Because I'm a genius."

Castle waved his phone around. "And yet, I found the connection when you... what's the word? What is the word I'm looking for?" He tapped a finger against his chin. "Oh yes: 'failed' to do so."

"Castle." Beckett said with humor, pushing him along to the point.

"You guys were looking for a connection, and I thought about what Sherlock said about how the hostages were chosen by convenience. There was no reason I could see why our Mad Bomber couldn't do the same with his puzzles, so I loaded all their photos into this new Facebook app. It lets you recognize faces in photos, so you can tag people. I figured if two of them were in the same photo anywhere, it'd be online."

"And you found a match?" Sherlock surmised. "Where? Which ones?"

Castle grinned. "All of them, except Klass."

Beat.

Sherlock looked to Beckett. "Fine; I take it back."

Beckett' shoulders straightened, pleased with herself.

Sherlock's mouth became a thin line, and he inclined his head toward Watson. "But my guy can still beat up your guy."

Coming from him it was so unexpected that Castle actually burst out laughing. "The connection is the Prep School Whitsett and Newbern went to. Newbern and his father posed for a photograph... and look who else is in that photo."

Sherlock had his smartphone out instantly, thumbs dancing across the screen. "That's David Doyle. "

"That connects our second puzzle to the third." Watson said, looking at the photo. "What's the connection to the first Puzzle?"

Sherlock was silent a moment. "London High Finance is an Old Boy's Network. Your business partners are all school chums and family friends. Strangers are uninvited. You made the point that wealth seems to be a running theme."

"Wall Street is too... international for that." Beckett shook her head. "But human nature is still the same. People stick with people they know and trust." She tapped the photo on Castle's phone. "We'd better look into this."

"Just because Klass isn't in this photo, it doesn't mean they don't know each other. It's a candid shot, and I don't know where it was taken."

Beckett's eyes flashed. "Newbern is in our holding cell. Let's ask him."

Newbern looked at the photo of Klass, his son; his wife; and all eleven mistresses. "No, I don't recognize any of them."

Castle held out his phone. "What about this guy?"

Newbern nodded at the photo Castle had found. "Yeah, David Doyle was a friend of my dad's. They met at some conference."

Sherlock reacted. "What conference?"

"I don't know, some pharmaceutical thing."

"Before he died, David Doyle was the main funding behind an experimental drug trial." Ryan reported an hour later. "Newbern's Father ran the trial; which was funded by David Doyle."

"What was the study for?" Watson asked.

Esposito checked. "Some new drug to treat Type One Diabetes."

"How many people are in the study?"

"None. After Doyle died; the checks stopped coming in and the study was shelved because the funding disappeared." Ryan reported. "But when it was running, there were five patients, plus two doctors."

"Bam, said the lady!" Castle said, a cat that got the cream. "I do believe we've narrowed things down quite a bit; wouldn't you say?"

"Yahtzee!" Ryan shouted and came over to join them. "Scotland Yard Detective Dominic Dargan, took a sabbatical from active duty seven months ago; so that he could come to New York to take part in an experimental program to treat his aggressive Type One Diabetes."

"There's the connection." Castle said quickly. "Dargan comes to America as part of his treatment."

Beckett picked up the story quickly, getting excited. "He goes to a clinic, meets the doctors; one of which is Newbern's father."

"One day Doyle comes by to see what his investment is getting." Castle kept going, both of them drifting closer together, working each other up. "Being a Scotland Yard Detective; Dargan finds out all these little mysteries that people of money and wealth have."

Beckett nodded eagerly. "He files it all away; until the funding gets cut and the trial is over. And with it, his career."

"He's spent his life chasing bad guys and the ones he doesn't catch are rich and powerful and never have to beg for the health, or their jobs... and something snaps." Castle put in.

"He's sees a chance; a chance to get revenge and be the one who has control; and he starts The Game." Beckett finished. By this point, Castle and Beckett were almost nose to nose, smiling broadly at each other. Watson sent a quick glance at Ryan and Esposito, who were making no effort to conceal their smiles.

"Hamish." Watson put in. "Just in case."

Castle and Beckett looked at him, confused. Sherlock waved at them to let it go; and the two of them quickly got back to work.

"I want a city wide APB on Dargan, starting thirty seconds ago." Gates ordered. "I'll tell State, and I'll call Lestrade, see if Dargan has any friends or relatives in New York. Run the usual search patterns; but he's Scotland Yard, so he knows our procedures. I doubt we'll find anything."

"I've already got Esposito and Ryan on it." Beckett nodded. "Dargan's been in the country for longer than he's been a mad bomber. He was staying somewhere during that Drug Trial. He was on the grid somewhere until then."

Out in the bullpen, the Pink Phone Rang.

Beckett looked to Gates, who quickly dismissed her. "Go."

Sherlock had already answered the phone. "Yes?"

"Hello?" A voice called from the phone; calmer but still shaky. "I... I don't know where I am. He said you have two hours. He said you have to tell me which key!"

"How many keys are there?" Castle called.

"Three." The man said, and the line disconnected instantly.

"Only three keys this time." Watson said. "That narrows it down a lot."

"And makes it far more likely that our hostage will try his luck before we can find the Magic Number." Beckett cut him off. "The longer we make him wait, the more likely he'll spook and pick one at random."

"And we only have two hours. Find Dargan, Detective." Sherlock told Beckett. "You can't play this Game, but I can."

Beckett nodded. "Can you keep ahead of him long enough to make sure nobody dies before I catch the bastard?"

"Our killer isn't Moriarty. He's pretending. The Real Moriarty could make these puzzles up as he went along, but the man we're chasing is working from someone else's playbook."

Castle nodded. "He's out of ideas, that's why the delay between calls. He's trying to come up with new challenges."

"That will give you enough time to manoeuvre." Sherlock said. "And make it more likely that he will make mistakes."

The Pink Phone beeped; and an image came up on screen. It was a poster for a concert; with the corner ripped. The poster was pasted up on a brick wall; though where it was wasn't apparent.

"I'll send it out." Beckett said, holding out her hand for the phone.

"Don't bother." Sherlock shook his head. "I have my own network."

"Your homeless network is in London." Watson pointed out as though Sherlock had forgotten.

"You didn't think I was sleeping last night; did you?" Sherlock scorned. "Come Watson, the Game's Afoot."

The two of them swept out, and Castle immediately pulled out his notepad. "That is such a great exit line!"

The Murder Board had a new addition; a large official photograph in black and white; showing all the investors, doctors and patients involved in a new experimental treatment for Type One Diabetes.

"Dargan went off the Grid four months ago. No trace of him anywhere. Lestrade has given us Dargan's list of contacts and alias'. None of them are in New York. No money transfers, no hits with his fingerprints in any Precincts. He just... walked away from his life; never to be found again."

"He would. He'd know we'd be on to him and he's Scotland Yard, so he knows the whole playbook. He'll never go back to any of his life ever again."

"How do you hunt a hunter?" Castle asked rhetorically.

"Same way you hunt anything. Follow his game trails." Beckett said swiftly. "He found the three puzzles; he must have a way in on them all."

"Right, that the Diabetes Study." Castle reminded her.

"The Drug Trial connects Newbern to Doyle. It was a business relationship through the father. But Klass wasn't involved in the Diabetes Drug." Beckett shook her head. "Neither was Joey, neither were any of Klass's family, friends, co-workers... So how does our bomber connect the first puzzle to the last two?"

"Maybe it doesn't connect." Castle suggested. "Maybe he just happened to find out about Klass and added his mystery to the list. Looking for a way to pad out the numbers?"

"The man had eleven mistresses, and hid them all from his wife." Beckett said with pointed disagreement. "He knows better than to leave things lying around. Dargan had to have a way in if he wanted details." She waved at the murder board. "We found the New York Sniper through a coffee shop he went to. What's Dargan's hunting ground?"

Ryan shook his head. "We ran everything since the first Puzzle, we know Klass better than his wife does by now. There's nothing that connects him to that Drug Trial, which is the only connection our last two mysteries have."

"Well there has to be something else; because Dargan found a way in to all of them. There has to be some way to put Klass with Newbern and Doyle; and if we don't find it... we'll never find out how Dargan come up with his puzzles..."

"Which means we'll never find him." Castle finished.

Long silence.

"Call him." Castle told Beckett.

Beckett's mouth became a very thin line. "I am not calling up Sherlock Holmes and begging for help with my homework." She said plainly.

Castle sighed. Long silence.

"You do it." Beckett said finally.

Castle drew his phone before she was finished speaking.

Sherlock looked. There was a shot of the drug trial picture. Familiar faces, unfamiliar ones...

The phone beeped again. It was a message from Castle. No Connection To Klass. Any ideas?

Sherlock studied the photo... and sent a response. "They're close." He said to Watson.

Castle checked the response and grinned. "The woman fourth from the left." He jumped up. "She's one of the patients in the drug trial... and she works at the Carlton Hotel as a receptionist!"

Ryan shook his head. "Sherlock walked past her, was in the same room for all of two seconds, just like the rest of us."

"That's the connection." Beckett said with certainty. "The Clerk at Micheal Klass' love nest went to the same clinic that Whitsett's father worked at."

"The hotel clerk?" Beckett said. "What's her name?"

"Tabatha Hynek." Ryan reported. "And she's on shift now, I think."

Beckett was already moving. "Let's roll."

Sherlock looked down at his phone.

Whitsett's father worked at Clinic. David Doyle funded the drug trial. The same clinic where Hotel clerk was treated for diabetes. Three for three. – Castle.

Sherlock smiled. "They've got their end covered."

Back at the Carlton Hotel, Tabatha looked at the photo of Dargan and nodded. "Yeah, I know him. I met him at the Clinic, when they were testing a new kind of Insulin shot. I met him again here. Small world, huh?"

"Not as small as you think." Castle commented under his breath. "This is a long shot, but do you know how to contact him?"

Tabatha looked over her shoulder at the key-rings to all the hotel rooms. "He's in room 109; looks like he's still here."

Beckett froze, one hand going to her gun automatically. "He's here in the building?"

Castle let out a breath in disgust. "We were right here during his very first puzzle. He was across the hall!"

Sherlock's new contacts in New York came through; and directed him and Watson to the place in the photo. it was a poster with the corner ripped. Sherlock was walking the scene in a grid; scanning in every direction; looking for a clue.

Watson's phone rang and he answered it quickly. "Detective Beckett? We're at the site of the latest- What?" He listened for a moment. "Understood, I'll let him know."

Sherlock glanced over. "Problem?"

"They found Dargan. They're on their way to arrest him. Castle and Beckett think we should solve this puzzle; because if Dargan doesn't tell us where to find the hostage, we may not have time for both."

"No." Sherlock was already moving. "We go after the source."

"Beckett's got that end covered with a whole Tac-Team." Watson protested.

Sherlock wasn't even slowing down as he almost ran back to the car.

"Sherlock, you said yourself that they've got it covered..." Watson sighed. "Wait for me!"

Tabatha quietly got people out of the lobby and closed the front doors. Maintenance staff sealed the ground floor, doors and windows.

The rest of her tactical team arrived quickly in full vests and riot gear. Castle had already collected his custom vest; and was helping Beckett adjust the straps on hers, when Javier whistled for her attention; and she saw Sherlock and Watson being stopped at the door. She waved to let them in; and checked her gun. "You guys shouldn't be here."

Sherlock's face was stone, even as he did a double take at Sherlock's bulletproof vest. "We're not sitting this one out."

Watson glanced at Esposito. "Don't happen to have a spare gun, do you? I couldn't bring mine across on the plane."

"A gun?" Esposito repeated in disbelief. "We don't even have a vest that will fit you."

"Don't feel bad. They won't give me one either." Castle empathized. "I had to pay for my own vest."

"Okay, tactical report." Beckett said over all of them. "The ground level has been sealed; backup is watching both entrances and the alley. We couldn't alert the upper floors without tipping off the bad guy; so there are civilians in the building; remember he's a bomber, so watch what you touch, check every door in the room. For those of you who don't know Sherlock Holmes and Dr Waston; they're important to the case, but if they get in the way; you have permission to shoot them."

A general murmur of amusement went around the tactical team. The kind of gallows humor that usually preceded a gunfight.

"You know the routine, Team One: the Door; Team Two: Sweep and Clear." Beckett laid it out, leading the way toward the elevators. "Civilians will stay out of the Hotel Room until we've cleared it of suspects, triggers and explosives. Is everyone clear on the plan?"

Everyone nodded. The elevator doors opened, and an old woman looked at the dozen fully armed police officers six inches in front of her; and stepped back against the wall. "Oh. Hello?"

Beckett pulled the old woman off the elevator without a word and stepped in; the rest of her team right behind her. Sherlock and the rest of the Tactical Response Unit took the stairs; unwilling to wait for it to come back.

The Police assembled on opposite sides of Dargan's door. Beckett sent them all a quick glance, making sure of their formation; and held her weapon ready.

"NYPD!" Beckett roared. "OPEN UP!"

"You'd probably catch more bad guys if you didn't scream out a warning." Sherlock observed.

"I agree." Castle put in. "How many times have I told you that?"

Beckett rolled her eyes and kicked the door in. She and the team boiled in the door, bristling guns... Every cop on the team spread through the room, searching every room, every closet; under the bed, behind the couch. Bomb making equipment was on the coffee table; as well as small portable televisions; showing feeds from different locations... Military grade jamming equipment was hooked up to the phone.

"Found him." Ryan called darkly.

Sherlock and Watson followed soon after and found their prey in the bedroom.

What was left of Domonic Dargan was hanging from the ceiling.

Written on the wall in his blood, was a message.

ACCEPT NO SUBSTITUTES!

Sherlock's mouth became a very thin line. "Moriarty."

Castle nodded. "He didn't like having a copycat."

Twenty minutes later, the Hotel Room was a crime scene. Sherlock and Watson watched as the body was loaded into a police truck for transport to the Morgue.

"They went through Dargan's equipment; found a location for the last hostage; she's fine." Watson observed. "So, I guess the case is over."

"So it would seem." Sherlock nodded. "I'm starving."

Watson rolled his eyes. "You only notice hunger when you don't have a case?"

"Thirst and sleep too." Sherlock nodded as though it was perfectly normal. Watson was leading the way down the street toward a crowd of people who were gathered around trying to get a look at whatever had happened. As seemed to be the case with all crowds; a hot dog vendor had set up shop close by. "Curious thing about New York." Sherlock observed. "It seems every thirty feet you can buy some form of food on a stick."

Watson ordered two hot dogs; and handed one to Sherlock. "Here. It's the American experience."

Sherlock took a bite. "Hm. Not bad; but I can probably tell you what's in it."

Watson nodded and took a bite. "I figured you would. Castle said under no circumstances did I want to know."

Sherlock nodded and headed back toward the crime scene. "He's probably right."

Watson fell into step behind Sherlock. "So. Can I try my hand at deduction now?"

Sherlock gestured grandly. "By all means."

"You knew Moriarty wasn't the killer after about five minutes. But you still sent him a message on your website. Once Beckett found the killer you insisted on being there in person, even though you knew the NYPD could handle the arrest. So I figure, you either want to flush out the real deal, or you want to set Moriarty loose on Dargan. It's not the former, because you knew he wouldn't take the bait. If it's the latter... You served that poor idiot up on a plate for the chance to get a shot at Moriarty. He was the bait; and Moriarty killed him because you pointed him that way."

Silence.

"Interesting theory." Sherlock commented. "But just because Dargan was out of his league doesn't make him a helpless victim, he blew up one person and tried to kill four more, so don't go painting me as the villain just yet."

An hour later, Team Beckett was making their full report to Gates; with Lestrade listening in over the phone. "Dargan was dropped from the drug trial. Budget cutbacks. He wasn't playing a game, he was bringing down the people that had kicked him to the curb. The new treatment could have vastly improved his life; but as it was he had to take medical leave from Scotland Yard."

"I don't know which ticked him off more: The fact that they kicked him out, or the fact that the people who decided to make budget cuts were the same people that were covering up murders and blackmail." Castle explained the back story. "He decided to get even."

"Revenge. Oldest motive in the book." Lestrade piped up over the speaker phone. "But what I don't get is, why like this? Why all the games?"

"When Moriarty played the Great Game back in London... I guess it inspired him. Maybe he was trying to shift the blame to someone else, maybe he just wanted to try it himself." Beckett guessed.

"Being in a room with that much brilliance is addictive." Castle said. "At some point, it wasn't enough to investigate the Criminal Mastermind cases; Dargan wanted to be one himself."

"A brilliant mind, frustrated at people he could run rings around; and he found the ultimate game." Gates commented. "Are we talking about our killer, or Sherlock Holmes?"

She'd meant it as a sarcastic remark; but neither Beckett or Castle, nor Lestrade on the phone, actually thought of it as a joke.

"You think she was serious about that?" Castle asked Beckett quietly as they came out of Gates' Office. "About Sherlock and our bomber having something a little too... in common?"

"Sherlock doesn't care about Dargan, he came here for the Game." Beckett said. "The only equal Sherlock has is Moriarty, and that thought consumes his super-brain. Smart money says Moriarty sees it too. The only one out there like him has vowed to destroy him. If Moriarty is half as obsessed as Sherlock is..."

"It's the difference between a passion and an obsession." Castle said sadly. "Sooner or later, your obsession will destroy you; win or lose; because it's the only thing left that you care about... and you don't care how much you lose; or how many people get hurt; as long as you get to keep going."

Silence.

Beckett sent a glance over at Castle. "You still talking about Sherlock Holmes? Or about my mom?"

Castle didn't answer for a while. "I... Kate, nobody on either side of the Atlantic can stand Sherlock; and that's because he's so single-minded that he doesn't care how many people he hurts along the way. When his case load stops; he starts to come apart at the seams, and when he does have a target; he's completely unaware of the fact that he's starving, or exhausted or thirsty. His obsession is all that sustains him. I worry about you sometimes; but not like that. Not yet."

Beckett shivered. "You think I'll be Sherlock in ten years?"

"What do you think Sherlock would do with himself if we actually caught Moriarty today?" Castle challenged. "Make no mistake; I've written this story through to the end with four different characters. It ends with Moriarty and Sherlock both lying dead somewhere; and their hands wrapped around each others throats until whomever is left comes to arrange double-funeral." Castle shook his head. "I don't want to write an ending like that for Nikki Heat."

Beckett raised a hand without thinking, and cupped the side of his face. "Rick, I... John."

"John?" Castle blinked, staring deeply into her eyes, until his brain caught up and he turned to see Watson standing very quietly over by the door; with his hands in his pockets. "John."

"Just dropped by to say goodbye, and thanks for everything." Watson said.

"Mm." Beckett shook his hand. "Thank you, for all your help. You and Sherlock being here saved at least three lives. Good luck with him in the future."

Castle reached into the bottom drawer of Beckett's desk and pulled out a hardcover book, tied with a ribbon. "Here's a little something for the flight back to London."

Watson beamed, thrilled. "Frozen Heat, by Richard Castle. I didn't think this was out yet!"

"It isn't, but the print run is done. Being the author has its privileges. Would you like me to autograph it for you?"

Watson tried not to seem too enthusiastic. "Please."

Castle searched his pockets for a pen. "Funny, I always have a pen right up until the moment I need one in a hurry."

"My desk, second drawer." Beckett said over her shoulder, heading over to clean the Murder Board.

Castle glanced at Beckett over his shoulder and lowered his voice. "John..." He said finally. "Do you think if I asked Sherlock to look at Johanna Beckett's case..."

"He might." Watson nodded. "He might not. Cold cases are hard to predict. I've known the man better than most for over a year now, I honestly can't tell you which way his mind will jump on any given topic."

Sherlock appeared in the doorway. "John, our flight's been moved up; we have to hurry."

Watson nodded; and the 12th Precinct made their goodbyes.

"Have a safe flight." Castle said brightly. "And if we ever have a case that brings us to London; we'll look you up."

"Yes, I'm sure." Sherlock said, in a tone that would have been sincere on anyone else.

Esposito slid over next to Castle. "You're thinking about turning Sherlock loose on Beckett's Mom's Case." He whispered. It was not a question.

Castle didn't answer.

Esposito shrugged. "I'd go for it."

Castle bit his lip and started to go after Sherlock, when his phone rang. "Castle."

"Don't tell anyone who's calling." Answered a soft, soprano voice.

"Okay." Castle said, nonplussed. "Who is calling?"

"Jim Moriarty." The answer came in a sweet sing-song tone. "Hi."

Castle froze; his eyes on Sherlock; who was calmly leaving the Precinct without looking back..

"I saw a photo of you in the paper a few months ago. The Margerson Kidnapping? Should have handled it personally, my own fault. Beckett wasn't bad." He paused. "It was an interesting photo though. Did you tell Beckett about the new lead?"

"I was just thinking about that actually." Castle said casually; very aware of Esposito close by.

"And thinking about asking Sherlock for help." Moriarty agreed. "Don't do that. Holmes is my playmate, and I don't like to share my toys."

"What do you care?"

"I don't. You're nothing. You're less than a flea. You and all the other sheep are so BLOODY BORING!" Moriarty suddenly shrieked, and Castle jumped.

His phone beeped, and Castle looked. There was a photo of Alexis on screen, taken from about ten feet behind her. She was just walking down the street; completely unaware of someone watching her. His blood ran cold.

Moriarty continued, like his previous outburst never happened. "Johanna Beckett's case is off limits." He said calmly.

"Why?"

Moriarty ignored the question. "I don't mind you taking copycats off the board. I'm one of a kind. But I have plans, and I won't have them changed by ordinary people. Keep your mouth shut, just for a few hours, and you will go back to being insignificant to me. By morning, I will have forgotten you exist. It's really the most I can bring myself to offer you."

Beckett returned to Captain Gates' Office. "Sir?"

Gates slid an envelope across the table towards her. "Lestrade sent it over."

Beckett opened the envelope, and slid out a large A4 size photo, or a man with pale eyes and a wrinkled sneer of contempt etched permanently on his thin lips.

"No other name, no other alias, no fingerprints, no paper trail, no DNA, no birth certificate, no bank records, no nothing." Gates never took her eyes off Beckett. "That's him?"

Beckett nodded. "That's him." She said softly, speaking the name, soft and cold. "Moriarty."

Gates nodded. "UK Police, as well as Scotland Yard and Interpol already have multiple warrants out for him. As of this evening, so does the FBI. Jim Moriarty is wanted for Murder."

Castle came home and threw his jacket at the rack instead of hanging it up.

"Long day?" His mother said when she saw him, but it wasn't really a question.

Castle looked straight through his mother. "Where's Alexis?"

"In her room; with a bucket of ice cream and a bottle of chocolate sauce." Martha sighed. "The Self-Pity Special."

Castle was already rushing upstairs.

Castle's worries evaporated the second he saw her. He never really thought she was in danger; the photo was taken without her knowledge; just a tap on the shoulder to remind Castle who he was dealing with.

Fear vanished, then he took in the way his daughter was clutching a spoonful of ice-cream; and his worry came back in an entirely different form. "You okay?"

Alexis sighed and sat straighter on the bed, as he came and sat next to her. "I'm fine. It's silly really; getting sad over nothing."

"It's called being a teenager." Castle said forgivingly as he sat on the edge of the bed.

Alexis smiled a bit. "I'll be okay; I was just in the mood to mope for a while."

"Alexis..." Castle said softly. "Could this have something to do with the boyfriend you're telling me nothing about?"

Alexis twitched. "How'd you know about that?"

"Doesn't matter. We don't keep secrets from each other, do we?"

Alexis smirked just a little through her red eyes. "To be fair; that's mostly because I heard about all your dirty secrets from the Internet... from the two divorce hearings. From the New York Times, from TMZ..."

"Fair enough. But your story I have to hear from you."

"Dad, I trust you, but the thing is, the whole 'cool dad' thing goes out the window whenever there's a guy involved. You become not-cool very quickly, and turn into..." Alexis hesitated. "What's the polite word for 'vicious'?"

"Doesn't mean you can't trust me." Castle promised her.

The young woman sighed. "I know... Look, he's not my boyfriend. Actually, he never was." She shrugged. "The... crush, I had on him has sort of run its course already."

Castle sat down. "How so?"

"He was only in New York for a few weeks. I think he was helping out with a lecturer in chemistry... I met him while I was auditing colleges."

Castle's face froze. "Wha..? How old is this guy?"

Alexis flushed. "Older than me. Look, nothing happened, never even held hands. But he was... brilliant, charming. And you can't be mad because he's already left the country."

Castle blinked. "If nothing had happened; why the aftershave?"

"That was actually his idea..." Alexis admitted. "I was surprised; because we'd only had coffee a couple of times. But he insisted; said it would 'get his attention'. And I went along with it because... Well, you know how it is?"

Castle hesitated, then let his face relax into an easy smile. "My baby's first crush on a teacher. What was Mr Wonderful's name?"

Alexis turned her laptop around and showed him the background image... making Castle's heart stop. There on the screen was a candid shot of his daughter in a cafe somewhere, with Jim Moriarty, each having one hand around each others waists; smiling winningly into the camera.

"Jim." Alexis sighed sweetly. "Jim Morris. I'm really going to miss him."

The Flight attendant's voice came over the PA. "The Captain has advised that the Fasten Seat Belt Sign is lit; and there is no smoking in the cabin."

Once the flight settled in for the long haul back to London, Sherlock pulled out his phone and began tapping away at it again. Watson pulled his laptop out of the overhead compartment, and began typing.

The Case of the Maybe Moriarty.

Hello to all my loyal readers across the pond. Thanks for having me and Sherlock as your guests the last week. For those of you who didn't know, a mysterious case has taken us to New York...

AN: So ends the crossover. If you enjoyed it; I would like to direct your attention to the button marked 'Review'.