A/N: What began as a response to a Rose Moss challenge (write a 2,000-words-max elder Spock/young McCoy ST XI story in a week) took on a life of its own and became something else entirely. Please note that in this story, elder Spock is in a committed relationship with the elder Doctor McCoy of ST:TOS.

Thoughts and telepathic communications are enclosed in asterisks.

Thanks to Rose and her insightful, sharp-eyed beta and encouragement. Mistakes are all mine!

Disclaimer: Paramount owns the Trek universe and its inhabitants...at least on paper.

Vulcan terminology:

adun-- beloved spouse

Kaiidth--What is, is.

-kam--affectionate diminutive attached to first name

katra--soul, life essence

q'omi--human (affectionate term when used with "my")

Shi'kahr--site of Spock's ancestral home on Vulcan

t'hy'la--lover, brother or friend; any combination of the three

What Shall Separate Us

"You know what must be done, Ambassador Spock," the Vulcan scientist quietly intoned, speaking for the scientists who had entered the room with him.

Spock did not turn around, but continued to look down at the elderly human sleeping quietly in the living quarters of the science laboratory. Spock sighed softly. His warm long-fingered hand gently pushed the old man's thinning white hair off of the wrinkled forehead. The aged right hand reached up reflexively at the touch, then settled next to the human's face.

Spock contemplated the man's hands. At age 150, Doctor Leonard McCoy was understandably frail, the blue veins prominent in the translucent parchment skin. Yet the vital-from-within spirit that had animated those hands was as young as the day they had met.

In his mind's eye he saw again a much younger McCoy performing delicate surgery on his father, Sarek…expertly bandaging a plasma burn victim in Engineering…gently comforting a badly injured yeoman in Sickbay.

And then Spock saw their first night together. He and the doctor had been debating once again in Sickbay, McCoy's hands punctuating one of his illogical rants. Spock had instinctively caught McCoy's bare wrists when the doctor had come too close. McCoy's startled expression had mirrored his own reaction. Those fascinating hands, deftly exploring him….

*One hundred years together. I wonder if it is possible to calculate how many times his hands have touched me.*

Spock closed his eyes at the thought and smiled slightly.

*No matter the number, the answer will always be…not often enough.*

From the corner of his eye, Spock saw the Vulcan scientists leave the room. They knew it was logical to allow Spock time with his human t'hy'la. The man was old and ill, but in no immediate danger. His Vulcan healers were always nearby. Proximity to both would keep Spock focused on the immediate concern. He would do what needed to be done.

After they left, the Vulcan's hand automatically found McCoy's meld points. The human stirred, his head unconsciously nestling into the heat of Spock's delicate fingertips.

*It is time, Len-kam.*

McCoy's eyes shuddered open in a blank stare, then focused on Spock. "Did I fall asleep again, adun? Dammit, why didn't you wake me?"

Spock's right eyebrow raised slightly, his brown eyes warm with affection. "You obviously needed the rest, Len-kam, or your body would have allowed you to stay awake."

The human made a face, and then grinned mischievously, his eyes twinkling. "I used to be able to stay awake a LONG time, remember? Of course, we were doing something a helluva lot more interesting than trying to blow up a supernova."

Spock's breath caught imperceptibly.

*His eyes are still as blue as a Georgia sky in summer, bright as the plantation lake sparkling in the sun. My q'omi….*

The Vulcan took McCoy's left hand in his own, caressing the cool aged fingers and gently tracing the pattern on the doctor's pinkie ring.

The old man squeezed Spock's hand. "So how long will this fool's errand take?"

"It is not a 'fool's errand', Len-kam. The people of Romulus are depending on us to…."

McCoy waved impatiently at Spock, motioning for him to help the doctor sit up. "Yeah, yeah, I know. It was a JOKE, darlin', a JOKE!"

Spock shook his head slightly in amusement, and then waited while McCoy put his thin arms around the Vulcan's neck. Spock lifted the human easily, a fleeting stab of fear causing his stomach to twist.

*So light, like a fledgling silverbird.*

The doctor's Georgian drawl broke his reverie.

"Well, you just gonna stand there, or are you gonna carry me over the threshold," McCoy teased as he settled against the Vulcan's neck and chest.

Spock's voice unconsciously shifted into a pedantic cadence. "I will carry you to the observation deck, doctor, and set you in your hoverchair. Sunak and T'Kir will care for you in the laboratory after the launch, and I will retrieve you when I return. I have already asked Healer T'Lar and Healer Skon to stay with you in the laboratory as well."

McCoy's head shot up and he studied Spock closely. "Well, aren't you the formal one. Doctor? Since when do you call me doctor?" His voice took on a tinge of sarcasm. "C'mon, Mister Spock, what's up? The job is pretty cut and dried, right? You blast off, shoot the red stuff into the sun, save the Romulans and come back. It's not like you're off on a five-year mission."

Spock did not reply, but continued to carry McCoy down the corridor toward the observation deck.

"Dammit, you pointy-eared hobgoblin, answer me! What aren't you telling me? It's not like I'm going to fall over dead if you tell me what's going on, you know!"

The Vulcan never broke stride but his body stiffened slightly, then relaxed.

McCoy's eyes widened.

"My god," he breathed, then was quiet for a moment. "That's it, isn't it? You're scared! You're thinking I might die while you're gone. Admit it…you're scared I'll die. "

The doctor's eyes never left the Vulcan's profile, but Spock looked straight ahead as he walked, his face a silent mask of concentration. Only his eyes betrayed the truth of McCoy's words.

*Why must you do this now, my q'omi...against you my heart has no shield, no defense.*

"What would you have me say," Spock said evenly as they reached the observation deck and he prepared to settle McCoy into the hoverchair.

The human's hand caught Spock's arm. He could feel the quick, uneven beat of McCoy's pulse in the doctor's fingertips. The Vulcan straightened up again.

"Adun," McCoy's voice became gentle and he turned the Vulcan's face toward his own. "I'll be alright, I promise. You gotta admit I've been a lot better since the last time I was in the healing center."

"You nearly expired," Spock replied quietly.

"But I didn't, did I?" McCoy reasoned. "I'm taking all the medsprays, and I'm doing the breathing treatments and drinking all those nasty tasting Vulcan teas. I'm feeling better, really. You'll be back in 12 standard hours, and then we can go home to Shi'khar and sit in the garden. Hell, we can plan a spring vacation to Georgia if we want to…yeah, why don't we do that?"

Spock smiled fleetingly at the animation in McCoy's voice, but said nothing.

"Dammit, Spock, I didn't mean to upset you." Sudden tears sprang into the human's eyes. "Hold me for awhile, will you?"

"I am not upset, my q'omi," Spock began, cradling McCoy as he carefully sat down in one of the deck's viewing chairs. "I have never contemplated having to leave you for any reason. To do so now is…. My duty is clear, and it is logical that I perform it."

The Vulcan pulled the doctor closer.

"But where you are concerned, t'hy'la, my logic fails me. There are many things I wish to say to you now, yet I have said them all many times. When I tell thee that I love thee and cherish thee, it is as wondrous as if it was the first time. The same joy that I felt that first time is now a thousand fold. Yet somehow the words seem inadequate. I…fear…."

McCoy's tears now flowed freely down his wrinkled face. The thin chest heaved convulsively as the old man gasped, "My god, Spock…."

Alarmed, Spock automatically put his hand over the doctor's heart, then retrieved a medhypo from McCoy's jacket and injected it into the juncture of the old man's left shoulder and neck.

"Len-kam, you will become ill again," Spock gently scolded as he put away the hypo and put his hand back on McCoy's chest.

"I'm alright, darlin'." McCoy wheezed, smiling weakly and covering the Vulcan's warm hand with his own. "I'm always alright with you here."

After a few minutes, the doctor's breathing quieted.

"Do you have any idea how much I love you, adun," he whispered. "Hell, I'm surprised this old heart hasn't ruptured from it. I wish I could put my katra in your head right now and you'd know, you'd know…."

"I do know, beloved, both here," Spock murmured, sliding McCoy's hand to his own meld points, "and here," pressing the doctor's hand against his own right side.

Instinctively, each man reached two fingers to the other, as they had done innumerable times before. A century of memories and feelings melted together, distilling into a warm, shining glow permeating both of their minds, hearts and souls, filling them to overflowing.

This time the illumination revealed the last of the dark places each had kept out of fear or embarrassment. Now there were no secrets, and each one knew and reveled in the other fully, completely. Regrets and mistakes were forgiven and transfigured. Triumphs and joys were celebrated fully, completely. Each filled the other.

Spock was still holding McCoy when the Vulcan scientists came to tell him that the ship was prepared and that the 'red matter' had been loaded. Quietly, Spock settled McCoy into his hoverchair. The old doctor's blue eyes were luminous and his mouth curved into a tender smile.

Once more, each man reached two fingers to the other. The Vulcan scientists withdrew silently. There was still time.

*Parted and never parted, never and always touching and touched, my Len-kam, my q'omi.*

*Parted and never parted, never and always touching and touched, my adun, my own darlin' t'hy'la.*


"I grieve with thee, Spock."

"I thank thee, Sunak, both for thy grief and for standing in my stead."

"It was my honor, Spock. He was a fine physician, a man of integrity and a worthy partner to the son of Sarek. I will guard his katra, as will my son and his son and my House, until it can be returned to Georgia as you have instructed. I have already contacted Captain Picard of the Enterprise, and he has said he will be pleased to carry us to Earth at his earliest availability. I shall leave for Enterprise immediately."

"I am grateful, Sunak. Live long and prosper."

"Peace and long life, Spock. Your service does all of Vulcan honor."

Spock wearily closed his eyes, his body still aching, remembering what had transpired just moments ago. His instruments had told the Vulcan scientists that the Romulan sun had supernovaed prematurely. He had hoped that the doctor would be asleep when he had confirmed that the resulting singularity would pull his ship into its maw. McCoy's anguished cry told him that his hope had been in vain.

He had felt the sudden rush of adrenalin and noradrenalin surging like a tidal wave through McCoy's aged veins and arteries, their by-products ravaging the doctor's cells. Small proteins produced by an overly excited nervous system rocketed their toxins to the human's racing heart, effectively stunning the muscle.

As he listened to the controlled voices of the Vulcan healers, he knew that his t'hy'la would not live. The doctor's gasping moans confirmed Spock's own experience of terrible crushing pain deep in McCoy's chest, a desperate shortness of breath, lungs filling with fluid.

Spock had done his best to comfort his life partner, tenderly cocooning McCoy in the strength of their bond.

*Parted and never parted, never and always touching and touched, my Len-kam, my q'omi, beloved.*

His life ebbing into a whisper, McCoy had strained to reply.

*Parted… never parted…never....*

Now all was silence.

Spock felt as though he was floating. He exhaled, suddenly aware that he had been holding his breath.

An alarm rang throughout the cabin.

He did not open his eyes.

The singularity was pulling him into the blackness.

*All that he was and is still lives. Kaiidth—what is, is.*