Summary: Jerry Tyson (3XK) is captured after Castle shoots him off the bridge. The killer is then tried and sentenced to life in prison. However when another killer emerges devoted to carrying on Tyson's legacy Castle must put personal feelings aside and seek out his nemesis' help or risk losing everything he loves. Post-Watershed and goes slightly AU afterward.

CHAPTER ONE

September 28

High Security Wing

To The Honorable Tyson,

I've seen your work. I've marveled at its detail. The preparation you took. Everything. You may have been caught but your reign brought a city of eight million to its knees. You've inspired me, Mister Tyson. I will carry on your legacy.

Your much devoted fan,

Dam

"Well that is a most delusional piece of composition. Heh, 'delusional'. That's a good word for the day."

Richard Castle stood outside of Jerry Tyson's polycarbonate glass cell, his face a myriad of unreadable emotions as he watched the notorious serial killer, now clad in prison orange, study the letter. The letter that was handed to him had come in an unsealed envelope to which Tyson had neglected up until now choosing instead to focus on the letter first. Castle had said nothing up to this point. He simply arrived alongside two prison guards who had handed both that envelope and two other similar envelopes to Tyson. Just as quickly as they had come they had left leaving Castle alone with this chilling predator. It was already well past nine on a cold fall night and this prison and this person were the last place and face on earth the writer wished to see.

"Hey Castle," Tyson said as he examined the envelope. "This is postmarked the beginning of August. That's almost two months ago. Prison mail is notoriously slow even for a celebrity like me but even my 'will you marry me 3XK' letters still arrive with some regulatory."

"No blondes, I imagine," Castle said, speaking for the first time since his arrival. His tone was accusatory and there was no mistaking the look of disgust on the writer's face.

"You know, they never leave in the girl's picture," Tyson said with an over the top sigh as he searched through the envelope dates looking for the next oldest letter. "But that trashy pulp they write? You could learn a thing or two from some of those lonely women. Makes your famous page 105 seem like a birds and the bees talk from the old folks."

"Cry me a river," Castle said, his eyes narrowed dangerously. "You lost your rights the moment you slipped that noose around her neck, Tyson. You want to blame someone? Look in the mirror."

"Yeah, but how can anyone stay mad at such a pretty face?" Tyson said as he opened an envelope with a letter dated a week after the first one. "You know, I feel a bit like Mister Rogers. You can be my own Speedy Delivery."

"If Mister Rogers were a horror story," Castle said with a grimace. Tyson looked the writer over again taking especially close notice to the taut rigidness of Castle's demeanor. He was pacing slightly and his usual immaculate style of dress appeared to be anything but. His wrinkled clothes suggested that they had maybe been slept in. His clean shaven face was long passed the bad boy five o'clock shadow and was nearing unruly. Likewise, his normally styled hair was a mess of tangles and in dire need of a good comb. He looked more akin to a swashbuckling pirate or a lumberjack than a member of the high society elite. Then there were the mannerisms. Castle's fists flexed as he waited, a nervous habit, apparently. Something had the writer spooked and Tyson could only imagine that whatever situation he had been facing for the past month had deteriorated to the point of near hopeless desperation. It was the only real explanation as to why Castle would seek his enemy's council now.

"To the Honorable Tyson," Jerry said as he read the second letter. He paused for dramatic effect and to even clear his throat, milking the moment and enjoying the sight of his enemy's duress. "There is little doubt in my mind that you have not received my first letter and that it had been intercepted by authorities. While annoying, this is not at all unexpected and were I a betting man I'd wager you won't receive any of my fan mail until I've pushed the stakes even further. Little do the police know that the situation has already reached that point. You see every kill I make, I honor you. Your gift. Your art. It has inspired me, yet, while many would call me a copycat I have decided to take what I consider to be both your best qualities and my own and combine them. Turn them into what I consider as much an art as a science that I feel will keep me off the scope of the police for an acceptable period of time. In short you have inspired me, Jerry Tyson, but I won't limit my method to simply copycatting you. I have mutated it. I have evolved it. And only now are our protagonists realizing the gravity of the error they made in assuming I was, but a simply copycat. Your disciple as it were, Dam."

"That was intercepted on the fifteenth; two weeks after the first letter," Castle announced once Tyson had finished reading.

"I can read a date..." Tyson said with a roll of the eyes and pointed to the postmarked envelope identifying the day that it was sent out. "But let's skip the rest of the lit for now and you tell me what it is my... 'Disciple' has been up to. How many bodies?"

"Fourteen women killed."

"You mean to tell me you let fourteen innocent women die before you finally swallowed that pride and came to me for help?" Tyson chided, "Why Castle, you have more blood on your hands than I do," Tyson said and admonished the writer with a cruel mocking smile.

"The killer doesn't limit himself to one city."

"Maybe after the department is sued for criminal negligence you and I can share a cell together."

"Tyson-"

"No I don't imagine he would," Tyson said in reference to the multitude of cities, "How long then before the pattern became apparent?"

"Law enforcement bureaucracy. I wasn't with the investigation at the time but it wasn't until the third body, the one in Vegas, did the feds get involved. By then this had been doing on for almost two weeks. It wasn't until another week, August seventeenth, did the Warden finally come forward with the letters he had intercepted from Dam to you," Castle explained. "The task force stayed in Chicago hunting down leads for a week before the girl was found in Times Square. That's when I got involved."

"And then what? Another month until you came to me? And all the while this sociopath has been out there killing?"

"No," Castle said. "From what we can tell he hasn't killed since he first started leaving the bodies of missing persons for us to find." Tyson's brow furrowed in confusion so Castle explained further. "With the exception of the first body discovered all of the women were killed weeks if not months before we found them."

"Which means he controls when and where you find them," Tyson said as the full truth of the situation dawned on him. Castle nodded. A moment of silence passed between the man and the caged animal. "When was the last body found?"

"One week ago," Castle said. "Once he hit the New York we were finding another body every two to three days."

"Which breaks the pattern," Tyson observed, "He has run out of bodies."

"No," Castle said with a shake of the head, "Something else happened. He..."

Tyson eyed Castle with a detached sense of curiosity as the writer struggled to come to terms with whatever it was he was trying to get across. He viewed Castle and his comrades much the same way he hoped the writer viewed him, with a predatory respect. You could respect the shark in Jaws as a powerful killing machine. Something that nature had perfected over eons of evolution to be an apex predator. You would respect that creature for the abilities it had. But that was about it. At end of the day it was still your job to kill the shark - though admittedly Tyson saw himself as more the shark than the town sheriff. He was beyond delusions and false perceptions… And the town sheriff? That was how Tyson looked upon the one person who had managed to match his own intelligence and bring him down. He didn't feel any sympathy or respect for this self-appointed 'disciple' of his anymore than he would care for a diseased cockroach. Castle had always been a formidable opponent and, in Tyson's eyes, worthy of his respect. But now? The man seemed a hollow husk, a shadow of his former self. When Tyson looked at Castle all he felt was disgust.

"He took her," the writer finally managed to say.

'Of course he did,' Tyson thought with a roll of the eyes. 'What a pathetic sap you have become, Richard Castle.'

"Why don't you start from the beginning?" Tyson suggested as he moved to the back of his cell and laid down on his bed. Lying on his back 3XK folded his hands behind his head and propped his head up, studying Castle with a cold calculating measure behind a gleeful grin of malice.

Whatever had been building inside of Castle had finally boiled over as his worn patience broke.

"What? There's no time for that!" Castle yelled, snapping at Tyson.

"No," Tyson said, "You had over a month. That's plenty of time, but you fucked up. Only came to me now and if you want to do this right then I want to know it all."

Castle was quiet for a moment, his brow furrowed in thought as he rolled the situation over in his head and tried to determine if this was really the best course of action. He wanted a solution and he wanted it now. He didn't have the time to entertain Tyson with every last detail of the investigations that led up to this point. However, as Castle read the look on Tyson's face, he knew he had no choice. This was his last shot and Tyson knew it. The 3XK would savor this moment for all it was worth. It wasn't like he got cable in here.

"Burn in hell," Castle said as he turned and began to walk away, but the taunting laugh of his most deadly enemy chased after him. It eventually caused the man to stop and look back at the cell that laugh had emitted from.

"And where will you go, Castle?" Tyson called after him. "Face it. You have no one left!"

"How did it get to this?" Castle said to himself and bowed his head for a moment in reflection of just how grave and out of control the situation had become. Eventually the crime solver turned on his heels, marching back to Tyson's cell. "I warn you, Tyson, if you waste my time-"

"You'll what? Throw me away for another lifetime? Please, Castle, this promises to be the most fun I've had in months. Now, I assume the situation you are facing is time sensitive?"

Castle glared at the sociopath but begrudgingly conceded the predator's point.

"It started after your trial, when Kate first moved to DC."

"Beckett left New York?" Tyson said in surprise, "Weren't you two star crossed or whatever it is you are calling it these days?"

"Not relevant," Castle said as lightning flashed and thunder cracked.

"I want it all, Castle," Tyson said with a tone that construed no room for argument, "And besides you never know what might turn out to be relevant."

"I should have aimed for your head."

"And I should have pulled the trigger in that motel room. Guess we're both fucked. Want to share some Rocky Road?"

Rain began to pelt the grounds outside of the super max while the two students of the macabre settled in for what was going to be a long night in the maximum security wing.

"Okay," Castle said at last, "This Dam persona this guy calls himself. We think he first grew enamored by you when your trial was top news."

To be continued...

Disclaimer: Don't own Castle or any of its characters or settings.

AN: This is my first foray into the Castle-verse and while I have seen the entire series I have yet to grow fully accustomed to writing its characters. Similarly I am new to writing mystery and crime-genre so I ask you to bear with as I endeavor to get it down. Other than that see my profile for more information and feel free to leave behind any questions, comments, or snide remarks.

-S