Summary: Rei Mori, a slayer, sacrificed herself for the greater good unknowing that she was pre-immortal. Now 300 years later she will find herself helping the current Slayers Buffy and Faith Summers, the only twins to ever be called simultaneously.

A/U: Chapter 1 starts in season 1 of BTVS, Prologue is set in late 1600s or early 1700s, haven't set Rei's exact age.

Disclaimer: Joss Whedon owns BTVS. Not sure who owns Highlander (can't seem to find a clear consensus, seems one author will claim one person or company while another will claim someone else. I own only Rei Mori and Dai Nakamura.

Author's Note: First off this story is inspired by several others. DaBillaman's Shared Destiny and my own Charming the Slayer (which itself was inspired by DaBillaman's Darling One). Second off, Dawn is going to be in this from the beginning as the younger sister of Buffy and Faith. She's still the Key just sent earlier than in canon.

PROLOGUE

Rei crouched peering into the darkness of the third floor landing. She knew that as soon as Dai Nakamura realized he'd been tricked into coming to place, he would become more dangerous than ever, which meant she had to proceed with caution.

Rei squinted into the blackness, but even her keen eyes could see only vague shapes and dim outlines. Using her double-pointed staff to probe the floor ahead of her, Rei moved forward with every sense on high alert. There'd be no plan B's now, no do-overs. Nakamura knew she was hounding him. Jyoti, her Watcher, was on guard outside, ready to try and intercept the vampire if he slipped through their net, but that was a feeble hope. Everything was up to Rei now, and if she allowed Nakamura to get away, he'd disappear into the night. Somewhere, months from now, far away, samurai would find a mutilated body, and the pattern would begin all over again — more victims' names to be entered into some book in the watchers' libraries.

She wasn't about to let one of the most notorious vampires ever to rise from the grave make a fool of her.

Quietly she stalked through the blackness with nothing but her instincts and the sharpened end of her wooden weapon guiding her. Then, as she stepped around an overturned piece of furniture, Rei noticed a dim light coming from above. She looked up a set of stairs and saw the door to the next and last floor standing open.

I've got you now, she thought. Just exactly where I wanted you to be.

Abandoning her cautious approach, Rei bounded to the stairs and took them three at a time to reach the door. There she paused, looking through the door into the room, surveying the place where Nakamura would now be forced to make his stand, seeing the various pieces of furniture that could give Nakamura plenty of places to hide.

Rei moved swiftly into the room, not wanting to get ambushed at the threshold. Keeping her deadly staff at the ready, she took position in the first open area she came to and was not disappointed. As she turned, she saw a dark shape fly from the shadows beyond the doorway: Nakamura had been waiting for her.

Rei lunged at the airborne vampire with her staff held high. Nakamura avoided it deftly, coming to land with surprising lightness atop one of the wobbly steel ducts.

The vampire sniffed. "Ah, I suspected as much. I've met your kind before, girl."

Rei whirled, bringing her staff to a low guard. Nakamura was stationary, making a tempting target. She could throw her dusting stick, but if she missed …

"Then we can save the awkward introductions," Rei said as she eased slowly to one side, seeking a position of advantage. "And get right on to the killing."

"Slayers," Nakamura said with a snort. "Always so arrogant. As if they've done something to earn their title, rather than just having it thrust upon them."

"Right, and being a blood-sucking menace is such a great honor. What did you have to do to earn that?"

"I only had to die," Nakamura said, rising from a crouch to his full, imposing height. "Are you willing to do the same?"

Rei answered, "You're only half-dead, buddy. But I'll be happy to finish the job for you." Then she charged Nakamura, hoping to catch him off balance. The vampire was too quick, however. With a phenomenal leap Nakamura sailed above Rei's rush, coming to land behind her as she swung round again. Seeing his position, Rei fought the urge to grin.

"Love to stay, Slayer," Nakamura hissed through a wolfish set of fangs, "but I haven't gotten through this many years by looking for new and glorious ways to get staked. Go find some other night-stalker with a taste for lumber and fame — and tell them I wished them good luck."

With that Nakamura turned and sprinted toward a window, just as Jyoti had told Rei he would. True to form, once his ambush had failed, his next move was to get away as quick as he could.

He wasn't willing to go toe-to-toe with a slayer who was equipped and prepared to fight. Rei might have tried to stop him had she not known what waited for him beyond the window.

The frightful drop to the ground was not enough to keep Nakamura from making the leap, but the yard of the monastery that neighbored the building warehouse was. Nakamura perched on the edge of the window sill, glaring at the monastery.

"As they say, it's not the fall that kills you," Rei quipped. "It's the sudden stop on hallowed ground at the end. Guess you'll just have to stay here and see what this arrogant little slayer has to offer after all."

The vampire menaced her with a roar that voiced a century of malice and cruelty just as Rei pounced.

As fast as she could move she covered the distance between them, her dusting stick angling upward to heart level in a single, practiced motion. Her rush took Nakamura by surprise — he could neither dodge nor flee. All he could do was face down Rei's attack.

The slayer slashed upward with the point of her staff in an effort to slip under Nakamura's outstretched arms, to reach and pierce his chest. Nakamura tracked Rei's movement, saw her set her weight low for the upward thrust, and with amazing speed he swept his hand beneath the point of her weapon. With a twitch of his shoulder the vampire spun and where his chest had been just a moment before there was only empty air.

But Rei's attack was in motion; its momentum carried her forward. Nakamura had been standing only inches away from the window. Suddenly the wind was hissing past her. There was a horrible, empty feeling in the pit of her stomach as her arms spun like crazy pinwheels. Head first she plummeted uncontrolled through the air, downward, anticipating the horrible feeling of snapping bone.

0 – 0 – 0 – 0 – 0

Rei woke in her room in Jyoti's home. She had been dreaming yet again of the memory of her failure, of falling and of pain. She wondered how many lonely midnights she'd get to spend staring at the ceiling before the shock of that last step, the terrifying sensation of falling helplessly, would fade from her mind. Why, she wondered, did the world have to be so dark when you woke up alone?

As if in answer to her question, she heard the light scuff of a footstep near the window. She felt guilty, but comforted by the presence of her friend.

"Jyoti," she said, "you shouldn't be staying up with me so late. Why don't you go to bed home and come back in …"

The figure emerged from the shadows of the window where he had been waiting. "Good evening slayer," Nakamura said. "I do apologize for disturbing your rest."

"Son of a bitch," Rei said calmly. "Get out of here. I'll scream and Jyoti and the monks tending to me will be in here before you can so much as touch me."

Nakamura was backlit by the reflection from the moon coming through the window, his grotesque vampire face made even more monstrous by the eerie illumination. Rei saw the long, ancient-looking dagger in his hand, its hilt adorned by a small charm of little bones and crow feathers.

"And what a feast that will be," he replied. "I believe I will start with the monk in the next room, or maybe your watcher. I bet he will make a tasty snack."

Rei glared at him. "All right then, Nakamura. Take a chomp on me. The monks may not know you're an unholy, but I bet they can still wrestle you to the ground and get a set of handcuffs on you. Hey, maybe we can even get the hospital chaplain in here with some holy water to give you a blessing before they haul you away. What do you think? Sound like a party?"

The vampire smiled, his wet fangs glistening as he walked around the foot of her bed. His eyes never left her face. "Bold words, Slayer," he said, "but I am afraid you mistake my intent."

"Hey, my apologies," she replied. "I know how you get off on terrorizing people who can't fight back. I figured this'd be just a little slice of heaven for you."

"You are very strong, slayer," Nakamura said, reaching out to stroke Rei's hair. "You are hardly the first to try and track me down, as I am sure your watcher told you, but you are certainly the first to back me into a corner. It was … quite an experience."

"Guess you're getting sloppy, Nakamura. Or maybe you're just more stupid than you realized."

"You have done well concealing your identity these past two years, but now? Well, finding a girl who survived a fall from a four-story building was not difficult. You are no longer the dark, mysterious avenger who hunts the night, preying on the blood brotherhood."

"Geez, you make it sound so romantic," Rei said. "You get that crap out of a handbook of some kind, or do you moonlight in poetry when you're not torturing little children?"

"I could kill you where you lay, slayer," Nakamura said, regarding the knife in his hand. "You know that as well as I. But I think we must pursue another course."

Rei stared at Nakamura's eyes and fangs. "What do you want?"

"You fought a noble fight, girl," he said. "You have a strength that I have not seen in ages. To end you here, pitiful, defenseless, would be an affront to the warrior spirit that is within us — within both of us. We are better than that."

Nakamura turned his back to Rei as he collected his thoughts. Rei looked at his unprotected back and wished she could summon the power for one more jab with a stake.

"As you know," Nakamura explained. "The slayer's strength — the mystical essence that is within you — is working on your body even now. You deserve better than to die in this feeble, puny human condition. I give you this, slayer, one warrior to another: I give you another chance. While you are here, while you regain your strength, you are safe. I will not harm you, your watcher or your family — nor will any other of my kind — until you are whole again. Not until you are a warrior once more."

Nakamura turned, his vampire's face now withdrawn and hidden behind a mask of humanity. "Then, slayer … then we will meet in glorious battle once more. Then you will have the opportunity to take me down, to turn me to dust, and finish your quest."

He raised an eyebrow. "I would suggest we shake hands to seal the bargain, but … "

Rei looked into his dark, close-set eyes without blinking, and realized how much she despised him. He had tortured and killed so many people, he had taken pleasure in causing agony and suffering, and he had left Rei herself crippled and weak. But those weren't the reasons she felt such sudden hatred toward him.

What she truly hated him for was what he was doing to her now. The lie that he was trying to lure her with, that was the cruelest thing of all.

"Get out of my room, you filth," Rei struggled to keep her voice steady and firm. She didn't want to give any indication that she'd guessed where he was trying to lead her. "If you're quite done with your speech, then get out. You may know what it's like to be a murderer, but you've got no idea what a warrior is."

"I will take that as a 'yes,'" Nakamura said smugly. Rei could see that he believed his trap had been sprung.

But as he strode casually out of the room, Rei knew what she had to do. She didn't like it, not one bit. But she had seen the one option Nakamura failed to anticipate, the one escape route he'd left unguarded.

Rei breathed deeply and began to ready herself to go down that path in the lonely darkness of her room.

0 – 0 – 0 – 0 – 0

A Sparrow perched on the sill outside the window of Rei's room, its beak pressed against its breast feathers as it hunkered down in the cold, unseasonable squall. Rei had been watching the bird for hours. When the gusts began blowing shortly after dawn, she assumed the bird would quickly fly away, but it didn't. It stayed out there on the ledge with its head down and its wings tucked in tight, holding its ground in a contest of will against the wind.

She heard Jyoti's soft footsteps as he came into the room, but she didn't look at him.

"Good morning, Rei," he said. "Your breakfast, I see, is awaiting for you. Would you like me to … "

Jyoti quit speaking when he caught sight of the long, black knife resting beside the plastic plate on Rei's bedside table.

Rei turned her eyes toward her watcher. "Nakamura came to visit last night," was all she said.

Jyoti's mouth dropped open. "Dear God," he said. "Are you all right? How did …?"

"Relax, Jyoti," Rei assured him. "If Nakamura wanted me dead, you'd have found a nothing but a bloody corpse beside this breakfast tray."

"But still, he was here," Jyoti said, wrestling with the thought. "He must have had a reason. Did he leave some kind of clue?"

"Slow down. We don't need to search for clues. He was kind enough to lay his plans out right in front of me."

Jyoti sat beside Rei's bed. "What is he … What did he say?"

"Oh, all kinds of things," Rei said. "All kinds of things about warriors and courage and honor. The short version of the speech is that he promised to leave me alone until I'm out of bed and back on my feet. He said he got off on the glory of battle, the spirit of the slayer, blah-de-blah … He said he wanted me to have another chance to fight him once I'm strong enough to hold a stake."

Jyoti nodded. "We must redouble our efforts, then. The watchers' council is most pleased by the signs of your recovery. You cannot …"

"Jyoti," Rei interrupted. "There's not going to be any recovery."

Jyoti's thick eyebrows came together as he shook his head in uncertainty.

"Don't you understand?" Rei asked. "That's what he wants. He came here to set us up, to inspire me to do everything in my power to heal and get better. To cling onto life for the very hope of the day when I may have another chance to stop him dead in his tracks. To set himself up as the biggest, baddest vampire target imaginable. No other reason."

"It is the destiny of the slayer to fight the forces … "

"Yes, Jyoti," Rei said. "But this fight's over. When the monsters start rooting for you, it's time to draw up a new game plan."

Jyoti's face was blank. "What do you mean, Rei?"

Rei's chin trembled as she closed her eyes. "I've been thinking about this since Nakamura left, Jyoti," she said softly. "This isn't what I want, but what other choice is there? I've got to … it's time to end this now."

Jyoti leaned forward and put a hand on the rail of Rei's bed. "You are talking about putting an end to your own life?" he asked softly knowing that her life would not end, that she was pre-immortal, that her death now would activate that immortality, though she did not know that. While he would remain her Watcher, her chronicler when she became immortal, he would also lose her as a Slayer. With her death and rebirth as an immortal the Slayer spirit would go on to the next potential. While she would still have access to her Slayer abilities of course, she would no longer be on the active roster either. And for that reason he did not want to lose her as his Slayer when she had already lasted past most girls into her twenties. So, firmly, he commanded, "No, Rei. This must not be done."

"And why not?" Rei gulped. "Please, think about this seriously Jyoti. God knows that's what I've been doing for hours now. I've been trying to find some other way, something else to do."

"No, Rei," her watcher urged. "You are young and strong. You have much of the fight left in you. And this fight is now more important than ever."

Finally the tears Rei was struggling to hold back began to pour down her face. She had no way to stop them or to wipe them from her cheeks. In her mind she saw herself working toward recovery with her watcher by her side. She had no doubt that Jyoti would keep on being a faithful companion, never faltering in his tireless commitment to his slayer, watching over her through her recovery rather than patrols along dark streets.

She wanted to shake her head, to cast out the hopeful, positive thoughts that threatened to undermine her resolve, but she couldn't. Nakamura had robbed her of the ability to make even that simple motion on her own. The strength and power of the slayer now came down to one, single choice.

"More important than ever," Rei repeated Jyoti's words. "You're right about that, Jyoti. And now what are you asking me to do to be part of that important fight? You said yourself that a full recovery is unlikely. Any kind of recovery is going to be a long way away."

"But this is all part of the fight," Jyoti said reassuringly. "A difficult struggle, perhaps, but this is what is necessary to fulfill your calling."

"How long, Jyoti?" Rei asked. "How long will that struggle take? Months? Probably years. And during that time, how many lives are going to be lost to Nakamura and the other vampires of the world? How many people'll die while I'm recovering?" She looked at him, knowing there were no answers to her questions. "Jyoti, I'm not going to let others pay the price for my calling."

Jyoti glanced down. "But if you give up … "

"There'll be another slayer called, like I was. That's how it works," Rei said. She shut her eyes, but the tears went on rolling down her cheeks. "Someone else will go on with the battle. Someone with arms and legs. Someone whole. It's time for me to let go, Jyoti."

"Rei, I know how hopeless this seems. You must understand that anger and despair are normal parts of the process of recovery. But just as a warrior must fight physical enemies, one must also fight against …"

"Being a warrior is not about fighting," Rei said. "Being a warrior means being a protector, right Jyoti? It means looking into the face of fear and pain, doing what others cannot do, no matter how scared you are. To give everything you have for the good of others, that's what a warrior does. That's what you taught me, Jyoti."

"I cannot …" Jyoti struggled to get the words out. "The job of a watcher is to guide and protect the slayer. To help her keep her focus through the times of uncertainty."

Rei sobbed, just once, then swallowed hard and bit back the grief before it could overwhelm her. "Jyoti, don't make me fight you for this," she begged through clenched teeth. "I can't do it. I don't have that left in me. I need your help now."

She opened her eyes as the façade of resistance faded from Jyoti's face. He looked at her with the same patient wisdom she'd seen many a time before.

"I can't believe I'm the first one to come up with this idea," Rei said at last.

Jyoti shook his head slowly. "No, of course. The council has considered this issue and has anticipated this option," he said. "I have been given certain … supplies in preparation for this eventuality."

"That's a lovely way to put it," Rei said with a bitter laugh.

"But Rei, despite some rather strongly held convictions among the members of the council,"

Jyoti paused, his glistening eyes locked onto the slayer's. "Despite no small amount of debate, it was resolved that a slayer's life has validity in any form. If we regard the slayer as nothing more than an expendable tool, then we are no better than the monsters we fight."

"You are much better than that," Rei said with one last smile. "Thank you, Jyoti."

Jyoti reluctantly slid his hand into the pocket of his jacket as if he was reaching for a concealed scorpion. He brought out a small, bottle. "You're sure of this, are you Rei?" he asked. "There is no need to rush into this decision."

She sighed. "Now. Jyoti, help me," Rei said. "Help me be a warrior one more time."

Jyoti looked at Rei lying there, gazing back at him, imploring him to help her take the final step of her journey. He knew it would not end here, not for her. And with the rebirth as an immortal, she would find her body healed. He was sure the council had thought of this also, they knew she was pre-immortal. While she would be removed from the active roster, he was sure the council knew as well as he that Rei would not rest; that she would continue the work that she had done that had made her the longest living slayer so far, and even in time seek Nakamura out. With a single nod, a solemn and respectful bow, he unstopped the bottle.