The Ultimate Serial Killer

Summary: While investigating a serial killer in Boston, Dr. Spencer Reid discovers something he can't explain to the rest of his team.

Disclaimer: I do not own Criminal Minds or Highlander.

Boston, MA

The FBI's Behavioral Analysis Unit was really stumped on this case. The profile they were working with made so little sense, it seemed they would never be able to identify their suspect pool. The un-sub (unknown subject) was organized, in that he sought out a particular type of victim: young men in their late 20s or early 30s, with shoulder-length dark brown hair and a muscular build. But the kills were always blitz attacks in dark alleys. He took no souvenirs that they were able to identify. The murders were single swift strokes of a long-bladed weapon, most likely either a long knife or a sword, given that these were beheadings.

Dr. Spencer Reid's geographical profile had shown a man who was familiar with the city, but had no specific comfort zone. The victims were all over the city, with little to no pattern as to where he was likely to kill next. And his cool-off time was also difficult to pinpoint; the times between kills varied too erratically. So they couldn't figure out when he would be likely to seek out a new victim. They weren't even sure of what the un-sub might look like. There were no age indicators, as anyone who knew how to use a sword could have done this. All they knew for sure was that this person was probably between 18 and 45, based on the strength needed to kill in such a fashion.

Dr. Reid studied the information they had gathered. None of it made any sense, though they had some help from an expert on swords. One of the victims had carried the business card of a dojo in his pocket, bearing the name of a Duncan MacLeod from Seacouver, WA. Penelope Garcia, their technical analyst, had tracked him down to a local hotel, where he was staying while he was looking for the owner of a sword he wanted to acquire for his collection. And he looked exactly like the un-sub's victims.

The man had turned out to be a Scottish immigrant, though he specialized in Asian swords. The pride of his collection was a Japanese katana, which he brought with him on all of his trips. MacLeod had pointed out to the agents that no one unfamiliar with using a sword could have used one as efficiently as their killer had. In order to kill with a sword, one must be able to not only lift it, but swing it accurately. This, of course, also explained why they were unable to find signs of their un-sub perfecting his MO. That would have been a part of learning how to use the sword.

As Spencer was trying to find a pattern to all of their information, he heard the familiar voice of his superior, Supervisory Special Agent Aaron Hotchner. "Reid, it's late. You should go back to the hotel and get some rest, start fresh in the morning."

Spencer turned to face the older man. "I know it's late, Hotch. But I think I might be onto something, here." He turned back to the board displaying the map of Boston, marked with the locations each victim was found. The young genius knew that those locations must mean something in terms of solving this.

Hotch sighed. He supposed it made sense, as Reid's mentor, Jason Gideon, had been the same way when it came to solving difficult cases. "Look, you'll probably have better luck figuring it out when you've had some sleep. Right now, you're exhausted from tracing leads that go nowhere. Everyone else has already gone back to the hotel."

Spencer was about to object again, but realized Hotch was right. He was no good like this. "Alright, Hotch. I'll see you in a few hours."

Both agents gathered the few things they were bringing back to the hotel. Hotch was on his way out the door just as Spencer grabbed his shoulder bag from the desk he'd co-opted for the duration of the case.

Spencer fully intended to go back to the hotel. He really did. But something was nagging at him about this case. And it involved Duncan MacLeod. The Scotsman was not telling them everything he knew, Spence was sure of that. But he also knew that the rest of the team would never accept this hunch. He usually tried to have facts to back up his hunches. He always had some reason for thinking that a particular unsupported theory fit the profile.

Spencer couldn't explain this hunch, even to himself. He just knew that MacLeod wasn't entirely what he seemed. So his feet took him in the direction of the dojo owner's hotel. He was a few blocks from the hotel when he heard the clang of metal on metal coming from an alley. The agent recalled that MacLeod resembled the murder victims and sprinted towards the alley the sounds came from.

Duncan MacLeod of the Clan MacLeod was searching for the Immortal who'd managed to avoid a challenge for the last few weeks. The news reports of people being beheaded, all of whom looked a lot like Duncan, had been really ticking him off. How dare this Immortal risk all of their kind by involving mortals in their Game?

Duncan had only caught glimpses of this man when they sensed one another on the street. Somehow, the other Immortal had passed over him when their eyes met, and alighted on other people. The Highlander knew they had to talk. This was obviously a young Immortal who had never learned the Rules of the Game beyond having to take heads to survive. The last straw was when the young idiot had gone and killed his contact for the sword he'd been trying to acquire for the last month.

While the complication of the deal for the sword was a problem that would be difficult to overcome, what most bothered Duncan was that he had grown to like the murdered man over the time they had been working together. As his enemies over the last four centuries had all learned, nothing could irritate Duncan more than hurting his friends. This Immortal had to be stopped as soon as possible. He would start by offering to be the younger man's First Teacher, but Duncan would take him down if necessary.

The odd buzz in the back of his mind alerted him to the presence of another Immortal. He turned to look for the one triggering it, instantly focusing on the young man holding his hand to his head like he had a bad migraine. New Immortals tended to have this reaction, not being used to this Sixth Sense yet. They usually got over it after a few months, if they had a Teacher to help them get used to the new life from the first. Duncan guessed he hadn't had one.

He walked up to the younger man and put his hand on the other Immortal's shoulder. As the young man looked up at him with pain-filled eyes, Duncan said, "We need to talk."

The younger Immortal narrowed his eyes in thought, before nodding. "Yes. We do." He waited a moment, until the buzz faded, then led the way to a nearby alley, where they could talk privately.

Duncan followed him until they were far enough in that no one could hear what they were about to discuss. Once his companion turned to face him, the Scotsman asked, "How long ago did you die?"

The man started in surprise. "How...?"

Duncan sighed. It never got easier to have this talk, no matter how many new Immortals he spoke to. "You are Immortal. So am I. We are not alone, as I'm sure you've figured out."

The younger man studied him suspiciously. "I may have met others. What of it?"

The Highlander crossed his arms. "I'm guessing you haven't had anyone teach you how to survive the Game?"

In response, the man drew a sword from his coat. "I've learned enough on my own. I don't need anyone's 'help' to make it."

Duncan held up his empty hands. "Obviously, you haven't learned a few key Rules. You can't go around beheading random people on the off-chance they might be after your head."

The man took up a fighting stance. "I'm a soldier, mister. I've been in war. You have to be proactive, or you're dead."

Duncan nodded. "Proactive is good. But you can't even tell who your enemies are, yet. You've killed four mortals just in your attempts to take my head. Is this what you mean about being proactive? Killing innocent people by the dozen to get one enemy? And that's if you're lucky. You need to learn how to identify your enemies correctly."

The soldier lowered his sword a fraction. "This all started when people attacked me, first. What do you mean by 'identify my enemies?' How do I do that?"

Duncan relaxed a bit as his companion lowered his guard. "That migraine you had when we met on the street is a part of it. As you get used to being around other Immortals, that will settle down into a faint buzz on the edge of your awareness. If you let me be your Teacher, I'll help you develop that sense. You'll also find that you can be good friends with other Immortals."

The sword was back up in a defensive posture. "You're tricking me. All the others just wanted to fight me, and take my head. Why are you stalling?"

Duncan backed up to give the nervous man some more space. "Those other Immortals were headhunters. We're not all like that. And all of us had teachers to show us the ropes. The first few years are the hardest, because there's always confusion after waking up from the First Death. And there are Rules to how we do things. Breaking those Rules can have dangerous consequences."

The younger man scoffed. "Like what?" Before Duncan could answer, he shook his head in annoyance. "Never mind. Enough talk. Draw your sword."

Duncan sighed in resignation as his opponent threatened him with his weapon. Reluctant though he was, the Highlander reached into his own coat to draw his Japanese katana. Following the ritual of Immortal combat, he stated, "I am Duncan MacLeod of the Clan MacLeod. Who are you?"

The younger man also fell into the ritual, slightly less smoothly due to his lack of training in this. "I am Sergeant Daniel Johnson." Then, he threw himself at Duncan.

Daniel was very good at this. He'd obviously been taught swordplay by experts. His style suggested proponents of a modern style of sword work, probably reenactors. Duncan found himself challenged by this young Immortal. Even after more than four centuries, he could still be surprised.

Their swords clanged against each other repeatedly, as they moved in the intricate dance of the duel in the confines of the narrow alley. Occasionally, their weapons cut into the stones of the buildings on either side of them. Duncan was vaguely aware of someone nearby, but focused on the duel. Whatever the newcomer intended, Duncan knew that any wavering of attention would result in him losing his head.

At last, Duncan overpowered Daniel and knocked him to the ground. The boy looked up at him, defiant to the end. Duncan raised his sword over his head. Stating, "In the end, there can be only one," he slashed down at his prostrate foe.

As he completed the killing blow, the Quickening began to gather. It flowed from the body, a mist appearing between the neck and severed head. The mist flowed into Duncan as he stood there, and lightning suddenly struck from the clear sky overhead. Unlike normal lightning, these bolts ignored the buildings and wires, striking Duncan himself, as well as blowing out the windows of the buildings on either side of him.

Duncan fell to his knees as the Quickening faded. This was shorter than most, because of the youth of the dead Immortal. Even so, the rush of the transfer of energy still exhausted him. No matter how many times he went through it, it never got easier to deal with. How did Methos get addicted to this, anyway? He knelt on the ground for several moments as he absorbed the new Quickening, breathing heavily from the fight and the pain of the transfer.

He looked up as someone entered the alley. It was Dr. Reid, the young man from the FBI team investigating the murders. Using his katana for support, Duncan slowly rose to his feet as the FBI agent approached him.

Spencer walked slowly towards the kneeling swordsman, gun in hand. A headless body lay nearby, its head just a few feet away from it, a pool of blood still growing around the neck of the victim. The live man slowly rose to his feet, leaning on his sword as he did so, and turned to face the young FBI agent. By the light of the street lamp at the entrance to the alley, Spencer was startled to realize that the victor of this encounter was Duncan MacLeod. "Mr. MacLeod? You're the un-sub?" In his shock, he'd fallen into BAU jargon.

Duncan took note of the drawn weapon in the agent's hand, but ignored it as he cleaned and sheathed his sword. It wasn't like it would kill him permanently. "Dr. Reid, I know what this looks like, but I can explain." At the young man's skeptical look, he sighed. "Look, I'm not the serial killer you and your team are looking for. He is." He nodded at the dead man he'd so recently killed. "I merely stopped him from killing more people. He was after me, and killed others instead. Our kind sometimes do stupid things like this in the beginning." He sighed and shook his head in exasperation. "Usually, they're more willing to listen to reason when it comes to being trained."

Confused, Spencer asked, "Could you explain this to me in more detail? None of what you just said made any sense."

Duncan ran a hand through his disheveled hair, pulling his hair clip out to fix it, before sighing again. "I'll explain when we get back to my hotel room. This isn't a good place to have this discussion." He indicated the alley, littered with broken glass, and blood still pooling around the dead body. Then, he pulled out his cell phone. "Just give me a minute to make a quick call."

At Spencer's reluctant nod, he stepped further into the alley to make his call. He spoke quietly, so all the doctor heard was that Duncan was talking to someone named 'Joe' about the young man the Scotsman had killed, whom he named as 'Daniel Johnson,' and some group he called 'Watchers,' who needed to take care of something important. Once the call was done, the two men left the alley.

Duncan took Dr. Reid back to his hotel room. While the young FBI agent tried to ask questions on the way, the older man refused to tell him anything until they were behind closed doors. Once he'd locked the door to his room, Duncan sighed and said, "Alright, Dr. Reid, you may find what I'm about to tell you to be very hard to believe. I very rarely tell someone who isn't one of us, but you need to know. I also need your promise not to tell anyone, not even your superiors."

Spencer frowned at this. "I've seen some bizarre things in my time in the BAU, but what I just saw definitely tops everything any one of the agents I've ever worked with has seen. You have obviously been doing something you want kept a secret. Since you haven't killed me just to keep your secret, I think I can promise not to tell anyone." He grinned sheepishly, recalling the last time he lied to Hotch. "This won't be the first time I haven't told my superiors something. It sounds like I'm going to have to come up with a convincing lie to explain this whole case and its conclusion."

Duncan simply nodded. He pulled his sheathed katana from his jacket and placed it on the bed. The jacket landed right next to it. The Scotsman pulled the chair from the desk and offered it to the agent. Spencer turned it around, and sat on it backwards, arms crossed over the chair back as he waited to hear Duncan's explanation.

Duncan sat down on the bed, crossed his left leg over his right, and took a breath as he began. "I am an Immortal. I was born in the Highlands of Scotland in 1592. My first death was just before my 30th birthday, and I have not aged since that day."

Spencer furrowed his brows. "Immortal? I've read some fairy tales that discuss immortal beings, but I don't recall any that were humans."

Duncan looked amused at this. "That's because any books discussing us are kept by a secret organization that keeps chronicles on us. They keep track of us, and look out for books that are misclassified in bookstores and libraries. Most of us aren't aware of them, because they are mortals who work hard to keep us, and themselves, secret from the rest of the world."

Spencer nodded. "So what about the man you just killed?"

"He was also an Immortal, though his first death was relatively recent. And there are others, as well, of varying ages. We meet all over the world to fight battles to the death. The winner takes the loser's head, and absorbs his power and knowledge. The last one standing wins the ultimate Prize."

Spencer was very confused. "What is this prize?"

Duncan shrugged. "No one knows. All we know is that it will help the winner rule the world. The Game has been in existence for millennia, and that's all any Immortal has ever been aware of."

This whole thing was very puzzling. "So, you exist solely to kill one another? That's some game. How do you learn the rules of a game where everyone's killing everyone else?"

Duncan sighed. "We aren't always fighting one another. I'm very good friends with a few Immortals. Also, the older Immortals will instruct the younger ones in the Rules and how to fight. The duels are always fought with swords. Some of the best fighters among the Immortals are experts in several forms of combat, and know how best to combine them to make the best use of each form."

Spencer began to work it all out. "So, you die and come back, learn from older Immortals as you go, and fight one another to the death for an unknown prize. And the only way to win one of these duels is to take your opponent's head.

"You know, this Game of yours makes no sense. I don't get what purpose there could possibly be in creating a species that exists solely to destroy itself. The Game is genocidal, by its very nature, and Nature usually tries to ensure the survival of the species that's most capable of adapting. The only reason Immortals could have survived this long is that your birth rate seems to exceed the rate of death."

Duncan couldn't help but chuckle. "We don't have a birth rate, per se. All Immortals are barren. What we do have is the rate at which people become Immortal. People are born with the potential to be Immortal, and we can sense the potential Immortals. But only a violent death can make a person Immortal. Once it happens, they must be trained to defend themselves, or they'll lose their heads to the first headhunter they meet."

Spencer's eyes widened in shock. "That means even children can be Immortal. They'd be left at a distinct disadvantage against adult Immortals, because they aren't as strong. Most especially since they would never be able to grow up."

Duncan nodded sadly. "Yes. So very few last more than a few decades after their first deaths. Some seek protection from adult Immortals. Others take advantage of their apparent youth and trick adult Immortals into taking them in, and ambush them when they least expect it." He rolled his eyes at this, recalling Kenny.

The boy was over 800 years old, according to their mutual friend Amanda, and had managed to convince Duncan he was only ten years old, and recently made Immortal. Things went downhill after the kid tried to kill Duncan's girlfriend Anne, and then Duncan himself. The boy got away from him not long after that.

Only months later, he teamed up with one of Duncan's enemies so the two of them could kill both Duncan and Amanda, one of Duncan's Immortal friends, who also happened to be a professional thief and Kenny's First Teacher. Duncan lost track of him after Amanda threatened to kill Kenny if the boy killed Duncan. (Duncan had been practically helpless after absorbing the Quickening of Kenny's ally.)

Spencer was horrified by his explanation. "But this makes even less sense than before. How would any species last so long existing in such a fashion?"

MacLeod shrugged. "We don't know why it is. We only know that it is."

When Spencer finally returned to his own hotel room, his head was still spinning from all the information Duncan had given him. This was unbelievable. An entire subculture transcending all international boundaries had existed since the dawn of Time. There was nothing like it in any book he had ever read. He considered Duncan's suggestion of speaking to his friend Joe Dawson about these 'Watchers' who kept chronicles about Immortals.

Speaking of... He took out his cell phone and called back to Quantico. "Speak, my little genius, and I shall do my magic," Garcia's cheerful voice answered.

Spencer took a breath, knowing he had to phrase his request carefully. "Garcia, I need to know everything you can find about Daniel Johnson, a native of Boston."

There was a slight hesitation from Garcia before she responded. "Is he a suspect? I was not told you had a profile."

Reid quickly considered how much to tell her. "We don't have a profile, Garcia. I've been doing some investigating on my own, and his name came up. I wanted to know more about him, and I know you have access to more records than the local LEOs (law enforcement officers)."

Garcia chuckled. "Flattery will get you everywhere, Reid. Give me a moment, and I will tell you what I can." She tapped away at her keyboard, and within a few moments, the computer tech was back.

"Okay. So Daniel Johnson is, indeed, a Boston native. Born in 1971, he led a typical middle-class lifestyle and went to a lot of medieval reenactments. He enlisted in the Army right out of high school, and was deployed in Desert Storm."

Spencer was shocked. The man was over 40 years old! And yet, he looked no older than 20, from what the agent saw of his face. He waited for Penelope to tell him more.

"His military record was spotless, promoted as high as sergeant. The only oddity was a patrol he was on, where he was near the edge of a bomb blast that killed the rest of the men in the patrol group. He was the only survivor, and... no one knows why. Based on where he says he was in relation to the explosion, he should have been dead like the others."

Sitting down on his bed, Spencer thought over this story. This would explain why he looked half his actual age. Johnson did, in fact, die in that blast. He had simply revived. Being the only survivor, no one knew he was supposed to be dead.

Penelope continued, "When he came back, he was discharged, and he threw himself back into reenactments. I have records of lots of time spent at Ren Fairs, increased sword training for mock duels, the purchase of a sword. He's worked steadily since his discharge, mostly for companies closely associated with the Society for Creative Anachronism.

"The funny thing is, all his recent photos look no different from his service picture. How weird is that?"

Spencer chuckled. "He must come from a family that ages well." He couldn't exactly tell her that Daniel Johnson couldn't age. "Thanks for the information, Garcia."

"No problemo, Spencer. Need anything else?"

"No, that's all I needed. Thanks." The profiler ended the call. Spencer decided that it was in everyone's best interest to let this case go dead. Besides his promise to Duncan not to tell anyone what he'd seen, it was highly unlikely anyone would believe him if he did tell. If Duncan had been completely honest, this case was closed, anyway. The un-sub they were after was now dead, killed by the same method which he had used to kill his victims.

However, Spencer felt that he should make sure of MacLeod's story. He decided it might be a good idea to call this Dawson. At the very least, he could tell the Watcher what he'd just learned about Sergeant Johnson. Spencer had no idea how these people got their information for their chronicles, so his information might be critical to them for increased accuracy of records.