[As calm as he seemed at his station on the bridge, Spock was restless… Meanwhile, in an imaginary world, an imaginary old man was writing imaginary scientific formulas.
Leonard Nimoy said Mr. Spock would survive him. Oddly, even if his prophecy was fulfilled, and besides his work in TV and movies Zachary Quinto inherited the role, it happened that with his passing, Spock Prime also passed away. Probably, the 2016 movie will be dedicated to Mr. Nimoy, but I wonder whether they are going to mention "his" Mr. Spock and explain why he is no more, or leave it to the IDW comics. As the character already died heroically in TWOK, I think he now deserves a gentle passing.
3º revision, February 2016. This work might still have some minor changes in redaction, typo corrections, grammatical improvements and science, but it won't have more chapters.
December 2016. "Star Trek Beyond" recognized Spock Prime's passing. It amazed me that this story actually fits in the movie's storyline. I just added one phrase, and now you can consider all of this happened some days before they arrived in Starbase Yorktown.
With thanks to Mr. Santiago González, astrophysicist, and implicit homage to Nicanor Parra, physicist and poet.]

The Missing Constant.

As calm as he seemed at his station on the bridge, Spock was restless. As he worked, couldn't stop thinking about the choice he had to make. Thankfully, the last weeks had been full of routine work, which allowed him space to muse while his hands researched for data and issued reports. Unfortunately, the lack of any incident left him with nothing to distract him from thinking.

His older self had told him "do what feels right", but, in this case, both options were logical, both were right, and both felt awfully wrong. Nyota, or a Vulcan wife? When his first pon farr arrived, if it ever arrived, where his instincts would lead him? Would he even have a choice? And if he were to be spared from his father's race drives, and the decision depended entirely upon his logic and, yes, his feelings, where his place was meant to be? Didn't he have a duty toward his people? But, did he have such an obligation to fulfill, he, a half-Vulcan? Would his… contribution even be welcomed?

Children. Children. If the Vulcans were to survive as a race, they needed children.

Was he, a hybrid, capable of fathering offspring? Of course, he could ask McCoy to test him, but just thinking of a way to pose the question to the good doctor made him shudder internally. Discarded option.

He knew he should discuss the issue with Nyota. He was aware that humans, especially human females, highly appreciated to share their feelings and intimate thoughts. And then, they became utterly angry or hurt by the sharing of some upsetting truth. Not always, but frequently enough to make him discard that option too. And Jim… How could he start to understand a problem of such a nature? There was just one option left. The most difficult one.

In the conversations he had had with his older self, this one had skillfully avoided giving him direct advice, and Spock had not dared to ask personal questions. Spock wasn't even fully aware of what he had been doing in New Vulcan since the establishment of the colony. As Mr. Spock gently questioned him about the people in his life and how he was growing, Spock always ended telling almost everything about himself, and getting enriched by Mr. Spock's observations, but he never got to know anything about the Other's life. Did he ever have a family? Did he have any regrets about the choices he had made? Spock had been wondering about that for too long. He could understand Mr. Spock's reticence, but this time he needed an answer.

And then, it happened.

Like what he had sensed when Vulcan was destroyed. But, instead of the billions of screams that still resounded in the darkest corner of his mind, this time it was like a whisper in his ear. Sarek, was his first thought. Then, he knew. Something like a drop of ice-cold water running down his spine. The certainty of his absolute loneliness.

His hands paused on his console and he kept staring at the screen. After just one second, he resumed his work. Nobody noticed, until the duty shift was about to end. Nyota called him to her station.

"This is for you, from New Vulcan. A load of archives and files. Do you want a tape, or do I forward it to your station?"

"A tape will be quite adequate."

She glanced at him as the recording was being made.

"The sender's code is a new one. Did your father…?"

"Thank you, Lieutenant."

He took the tape from her console, and went back to his station. Nyota kept staring at him.

Three days later, he still hadn't opened the archive tape. His withdrawn behavior had been noticed by everybody on the bridge. He could feel their eyes following him as he worked, swiftly, efficiently, and completely detached of everything and everybody. He overheard Jim and Nyota whispering.

"Don't worry. It's just him thinking very hard. If it were something about the ship, he would tell me. If it were something about you, he would tell you."

"But, if it's something about himself…"

"Hm."

Finally, McCoy suggested a check-up. The concern in the doctor's voice had irritated him, and as he heard himself refusing not quite politely, the illogic of his own behavior appeared shamefully evident. Denial? Him? Enough.

He finished his shift, went to his quarters, and checked the archives. They were huge. "Vulcan Cultural Heritage Project" included files for everything from plomeek soup's recipe to a detailed description of Fal-tor-pan ritual. "Field Research Reports" was very basic, but very wide. "Mother" and "Recommended Readings". Spock left them for later. Finally, a single file titled "Letter". Spock read it carefully and with growing uneasiness. It was not a letter. It started like one, but then it became a sort of essay and at the end a collection of random notes verging on incoherence.

He called to the bridge and asked for a channel to New Vulcan, directly to the code name and private transmitter Ambassador Spock was using. The call was automatically forwarded to some Alien Student's Residence.

A face he didn't know appeared on the screen. A Romulan woman. An image from his nightmares.

"Jolan'tru."

He froze. She smiled, and waited calmly until he was able to speak.

"Excuse me. Professor Selek?"

"He died. Three days ago."

Spock kept silent. He knew that it was true, but still the confirmation was hard to accept. And now, what could he say to that unknown woman, that enemy? She smiled again, knowingly.

"I know who you are. Mister Spock told me."

So, Mr. Spock had revealed his identity to a Romulan? Even worse. But, unfortunately, it seemed that there was no other way of obtaining the information he needed. He tried his best to remain calm. At least, to seem calm.

"Why was I not informed?"

"Nobody was informed but those with which he worked. The authorities have sent a delegation to notify you properly at your next port of call. He left instructions for me to send his archives to you and wait. He said you would call if you considered it necessary."

"And you are?"

"One of his students. Did you read the files I sent?"

"Not entirely. How it happened?"

"It was early morning…"

Humming a melody from her home planet, the Romulan student came into the professor's study carrying a breakfast tray, as she did every day. It wasn't an obligation, but a service she performed with all the love and respect her old teacher commanded from her. She was surprised at not finding him as always, already working at his desk. She left the tray on it and looked around. The patio door was open.

There he was, seated on the bench under the pergola, looking at the vine that shadowed one of the patio's corners. The soft rustle of the salan-rarav sitting on the branches broke the sunrise silence.

"Your breakfast, sir."

He didn't answer. She came closer, and saw he still wore his nightwear, and was wrapped in the bed cover, even though, as usual, it was a warm morning.

"Sir?"

He looked at her, raised slightly a hand and gestured toward the vine.

"In every Class M planet in my knowledge, there is some class of flora, fauna or rock formation that produces harmonious sounds. Fascinating."

She looked upwards, at the big yet harmless insects feeding on the vine's blue flowers.

"I did not know that. It is indeed. Do I bring your breakfast here?"

"It will not be necessary."

"You have barely eaten in the past three days. I called a healer."

"That will not be necessary either. I know what is happening to me."

"I did not know you are a physician."

"I am not."

"In that case, your diagnosis might be wrong."

He looked at her, raising both eyebrows.

"Your progress in logic is most remarkable."

"That is called common sense, sir."

He looked at the vine, and it seemed to her he was smiling.

"Well, Commander. Proceed as you wish."

"You know I was just a centurion."

"And you know I have had access to that information."

She half smiled. When he spoke like that, she never knew whether he meant Federation's confidential documents or some secret personal knowledge. The doorbell rang. One of the Human students, a blond and lanky young man, opened the door and called her. The healer had arrived.

"Excuse me."

She went hurriedly to welcome the healer.

The Human student was by the door, looking at the visitor with both curiosity and wariness, even if the short, dark-skinned human healer looked anything but menacing.

"Live long and prosper," the Romulan student said.

"I come to serve," the healer answered.

"Your service honor us."

And they smiled at each other. A Romulan and a Terran had just exchanged the most polite Vulcan greetings.

"Where is the patient?"

"Please follow me."

The Human student followed them to the patio, but stayed apart. The young healer went close to the professor, as much as Vulcan good manners allowed. The professor looked at him keenly. His face, uniform and insignia.

"You are a Starfleet physician."

"I am Doctor M'Benga. I was assigned to do my internship in New Vulcan. I have just completed it."

"Of course."

The healer put his bag on a table by the bench and took his medical tricorder out.

"May I?"

"Please proceed."

As Dr. M'Benga scanned the professor slow and carefully, the Vulcan kept looking at the vine. The healer's face became somber.

"Can you describe your symptoms?"

"I am just… very tired. All bodily functions have been steadily decreasing for 9.5 days."

"How old are you?"

"162.7 of your years."

Dr. M'Benga seemed confused. He checked his instruments.

"I am half-human. Probably that accounts for some slightly unusual readings, and surely a lifespan shorter than the Vulcan average."

The healer adjusted the instrument and scanned him again.

"I believed the only Vulcan-Human… a young Starfleet officer… your birth would have been recorded… an interspecies…"

The professor interrupted the healer's mumbling.

"Your diagnosis?", he said, softly.

Dr. M'Benga finished the examination and checked the results. He left his scanner aside, and remained silent for a moment, although he knew that Vulcan patients don't care about bedside manners. They prefer objectivity.

"I think you have arrived to the end of your natural lifetime."

The professor nodded calmly.

"How long?"

"Your heart is failing. Today. Soon."

"Agreed."

The Romulan student went closer to the healer.

"But, surely there is something you can do…?"

"Not at this point."

The Human student ran inside the house. From the patio, they could hear him screaming, calling frantically the other students. Dr. M'Benga, ashamed of that behavior, attempted to make an apology. The professor just shook his head slightly. He was used to emotional humans' reactions. Dr. M'Benga composed himself.

"Sir, I am required to ask you who is your designated keeper."

"It shall not be a keeper."

Dr. M'Benga was totally taken aback.

"Sir? I… I have been told that it is something of the utmost importance, specially nowadays…"

"Certainly. But it is not mandatory."

"It would be a breach of my duties as a healer…"

"If someone questions you, you can say I refused. You have witnesses."

Dr. M'Benga looked around. The students were congregating in the patio, keeping a respectful distance. The Romulan student kneeled beside the professor.

"Mister Spock, are you sure?", she whispered anxiously.

"I am."

Dr. M'Benga had overheard the name. He leaned over the professor.

"You are the one… who came from…," he whispered, in shock.

"I am the reason you are not in Vulcan, but here instead."

"I… understand."

Dr. M'Benga drew himself up and took a step backwards.

"And from here, where is Starfleet sending you?"

"I do not know yet. I hope to be assigned to Starship Enterprise."

"It would be good. That young officer might have an occasion to thank for your services as much as I do. You may leave now."

His face contracted slightly. The healer took his scanner.

"I prefer to stay."

Dr. M'Benga scanned the professor quickly.

"Do you want a sedative?"

"No, thanks… I want to remain fully conscious."

All the students had already arrived. They came closer to their beloved professor. He looked at them one by one. Different skins, different blood, all of them young, innocent, and caring.

"Thank you. I have learned so much from all of you. A privilege…"

Some students were crying, others smiled at him. All of them raised their hands, opening, joining, waving or fluttering them, everyone according to their own traditions. And then, they all blessed him with a Vulcan salute. The Romulan student was the only one who could speak.

"Thank you, sir."

"Live long and prosper, dearest."

His voice was just a whisper. He started to collapse.

"It is getting closer…"

Dr. M'Benga left his things aside, took a seat by the professor's side, put his arms around the Vulcan and held him firmly. Mr. Spock slowly rested his head over Dr. M'Benga's chest and closed his eyes. The salan-rarav began whistling softly above the vine.

And then, it happened. He opened his eyes and smiled. A wide, boyish grin of pure wonder.

"Te'elis… The missing constant…"

That was all. His eyes closed, and he was gone. The salan-rarav took flight and left.

"Doctor M'Benga and me prepared his body. He had arranged that his remains be cremated, and so it was done."

Spock kept silent for some moments. When the Vulcan raised his eyes and looked at the Romulan, he didn't see an enemy.

"What is a Te'elis?"

"It means 'song' in Romulan. That is how he called me. My real name and profession are confidential."

"I see. It is a beautiful appellative. And then?"

"There was a brief ceremony at the funeral home's garden. Delegates from the Federation Science and Cultural Offices, and from the New Vulcan Science and History Academy thanked him for his efforts. Our Andorian classmate played in Mister Spock's ka'athyra a little tune he had taught him. A Terran song, something about a boat. Afterwards, we all climbed the highest hill around the colony and scattered the ashes into the wind. "

"Did Ambassador Sarek attend the funeral?"

"No."

Spock frowned slightly. She noticed.

"See. Mister Spock started a project for having Vulcan cultural history physically recorded, including everything never before revealed to out-worlders, copies of the archives sent to Memory Alpha, and have that planet shielded. Ambassador Sarek did not agree. He came here and they had a long conversation. When he was leaving, the ambassador embraced him. I had never seen a Vulcan doing that."

So that was what happened, Spock thought. He remembered his father doing that to him as a very last resort, that only time in his childhood he had lost all emotional control and just couldn't stop crying.

"Do you think Mister Spock was… that he had lost his mind?"

She considered.

"No. I do not think so. Rather, he seemed like having found something. Or realized something. When he passed, he was ready."

"I mean in the time before his death."

"I would not say so. He was very active, almost to the end. He was keen on the preservation of Vulcan culture. He researched and recorded every piece of philosophy, literature, history, ancient legends, songs and traditions he could find or remember."

She suddenly smiled, almost to the point of laughing, tough her eyes were bright with tears.

"Last month, he led us in the search of a sehlat equivalent. We could see how pleased he was, climbing hills with a tricorder in his hand like a man half his age. Basically, he was a scientist."

"A sehlat?"

"Do you not know that a Vulcan baby was born a month ago?"

"I know."

"The first one who has been born in New Vulcan. It has been the closest thing to a public festivity around here. But after that, the Elders realized that traditionally the child is supposed to have a pet, a sehlat, and no one had survived. The biologists might have recreated it using genetic data, but introducing a predatory species in this environment would be problematic. So, before trying that, the Elders requested to examine the local fauna for something alike. There was not an available zoologist, so we were asked to make the best possible ethological research on the major predator species. The results are pending further studies, but ours are the fundamental discoveries. And, in addition, since this house was opened to alien students, he tutored all of us. All what I know about Vulcan culture I learned from him. It was an honor…"

And she raised an eyebrow. Spock's confusion could be read on his face. He looked at her, and finally he burst out in an obvious question.

"Excuse me, but I have to ask. How is it that you, a Romulan…?"

She looked at him squarely.

"I was a Romulan Fleet officer. After what happened, our government is in a hidden turmoil. The Federation's top secret report that it was a Romulan from the future the one who attacked the Klingon Empire, the Federation itself, and destroyed the planet our ancestors came from… and the warning that in some time a supernova will be the cause of Romulus's destruction. They refuse to believe it, and have kept the information from the Romulan people. Several of us protested against those measures and left our home planet. The Federation granted us refugee status, unofficially. Some of us have come here. I wanted to help our distant brothers teaching them what I know about warfare. I never imagined I would become a Vulcan law student."

"You abandoned your post. Unthinkable for a Romulan officer."

"Yes, I am a deserter. We are trained to obey, discharge our duty and never surrender. But, what is the use, the logic, in defending a position that is lost one way or another, and leads to our complete annihilation? As I see it, by being here I am fighting for the preservation of my race as well as yours. Anyone can wage war. Building peace is a far tougher challenge. I used to crave power. I was willing to kill and to gamble my life for it. Mister Spock taught me to stand up for ideals. If we Romulans, Terrans and others can live together here, one day the Neutral Zone will become obsolete. We are strong, each one of us. Together, we would be stronger."

"I understand."

He thought that it was a curious version of the IDIC philosophy. And he thought that it was too much optimism against all knowledge and past experience. But Romulans are passionate people, he said to himself. He was too much a logical man for that. Too much a scientist. Althought…

"One last thing. He mentioned in his letter a certain scientific problem he was working on, but it is not included in the archives you sent. Where is it?"

"Ah, yes. In his last days he did not go out much. He was working on some sort of huge equation for an astrophysics model, or theory, I do not know. Totally beyond my level of understanding. He kept on saying that there was a constant missing in the formula for making it work. He wrote it all in Vulcan calligraphy, on a wide sheet of drawing material, pinned it to a wall, and kept on adding things almost to his last day. We took it to the New Vulcan Science Academy. They could not understand it. There was a mix of symbols and words in different languages. They said it was not logical. Doctor M'Benga took it to the Science Office at the Federation Outpost. They had a hard time rendering it all into Standard. And they did not understand it either. They said it was not scientific. The Cultural Office's librarian took a look at it. She said it was poetry."

Spock raised both eyebrows. She smiled.

"Yes, I know. Well, I have something for you. His ka'athyra. Should I send it to you?"

"No… I shall take it when I visit New Vulcan."

"I kept the equation too. Maybe you can solve it."

"Of course. Thanks."

"Anything else?"

"Not at the moment. Thank you very much. Live long and prosper."

"Peace and long life."

Spock opened the tape and perused the "Recommended Readings" file. He was amazed, not much by the amount, but by the genres. Mostly human philosophy, arts, literature and history. He could recognize himself in that need to understand human emotion that was beyond scientific curiosity. He didn't open the "Mother" file. He wasn't ready to read it. Not yet.

Then he read the "Letter" again. He couldn't fully understand it, but somehow it made more sense:

"Live long and prosper.

This time I can say it with no hint of personal gain implied. I have noticed my life is near to its end. This letter shall be the last communication between you and me.

I have prepared a collection of files to be sent to you after my death. Most of their content is intended for the "Vulcan Cultural Heritage Project" and you already know it; I want you to keep a copy. There are also records from the mineralogical classification and the local flora and fauna's taxonomy. As this planet is your new home, I think they will be useful. There is a list of books I have read with some commentaries, which I hope you will find both interesting and inspiring.

I am sorry you have lost Mother at such a young age. I wrote some things she told me about herself, about Father and myself, which are not information that could alter your future, but a way you can have a better knowledge of her.

Please give my best regards to your Captain. He is very different from the man who once was my t'hy'la. Nevertheless, I saw in his mind the same qualities that made me to be his friend, and him mine, which you are still discovering.

I could see your disbelief when I called McCoy "a friend". I agree the man is at best an acquired taste, but one I hope you learn to appreciate. I have missed him. Do not tell the good doctor I said that. At any rate, he would not believe it.

Enterprise. The finest starship in the Fleet.

I am glad you never asked me specific questions about your life. Indeed, even if I had wanted to answer them, I would not have been able to do it. This time, your life, are completely different from the one I knew. You are someone other than who I am, and in some ways you are becoming more and more different as time passes by.

When I was the only Vulcan on the Enterprise, no one could beat me in hand to hand combat, not even my Captain. I had not realized how much I prided myself on my physical strength until now, when it is declining rapidly. I think that, as a race, we Vulcans were like that: proud, self-sufficient. Now we are an endangered species. Was it that what we needed to learn a lesson in humility?

Humans use to say, "after all, we are only human", meaning that they are weak, frail, fallible, and curiously, they take comfort from that fact. We Vulcans never say anything alike. Does it mean that we are something else, something more, something better? Or that we believe we are? Is it not racial pride?

An old friend of mine once said to me: "Everybody is human". At the time, I found that remark insulting. Now I think I understand it. We all sentient beings are weak, frail, fallible.

When we presented ourselves as the teachers of the Galaxy, many admired us, but I do not think they even liked us. Now that we are in need of help, they have begun to care about us. Love us?

I live in a house full of young people coming from all over the Quadrant. There is an Andorian in here, in spite of everything. Even Romulans have come here too, defying both their Empire and the Federation, to learn, to help, to serve. Our race, in its essence, shall not disappear. Now I am sure of that. Surak's teachings, IDIC, are going far beyond we Vulcans ever thought it was possible.

I have officially bequeathed this residence for it to be a permanent home for the alien students living in New Vulcan. Works of art, tapes, books and other objects are included. My personal things are of no importance. However, I wish you make use of my ka'athyra. It is a new model. A Deltan student was able to make it just from description and images. He added a set of strings for sympathetic vibration. The resulting sound quality is outstanding.

I have a confession to make: I used to say that one must have faith that the Universe will unfold as it should. For a while, I lost faith in my own words. I came to believe that my life had been a failure. My last endeavor as an ambassador was to achieve the unification of Romulan and Vulcan people, and as a scientist, to stop a supernova from destroying billions of lives. I was ready to give my life for the greatest of all goods. What happened was that in my time Romulus was destroyed, in this one Vulcan was destroyed, and I lived to witness it. That could not be something that should happen, is not that so? Logic told me that I had done nothing wrong, but the feeling that my beliefs were false and my very existence had been a total failure kept growing inside me for a long time.

I have had several families. You and me have shared two of them, first our birth family and then our brothers and sisters in Starfleet. It is a pity that we, as Vulcans, tend to outlive our dear Human friends, but that makes their friendship even more precious. Later, there were other families. And now I have a family of children, my students, who fill my days with unexpected love, joy and hope. My beliefs came back to life. My students took that sense of failure away.

This universe, and its unknown future, it is yours to explore and admire. Do not be afraid of making decisions, of making mistakes, of asking for help. You are not as alone as I once was. You never mentioned it, but if you are someone like me, I know that in the darkest corner of your mind you are still thinking something like you were somewhat responsible for what happened and you must atone for it somehow. Let me assure you: you could not have reacted to Nero's attack a second faster than you did. If any of us is to blame, that one would be me. Let me take the burden off your shoulders and carry it away with me. I was the one who arrived too late. It is not self-loathing anymore, it is just a fact. I am still learning to accept it. Nightmares are becoming less frequent.

Father came to visit. He is not the man I knew as my father. Nevertheless, he is Sarek of Vulcan, and as always he made me feel like a small boy in his presence. That must be a constant in every timeline or universe. If it is possible for you, stay with him in his old age. He will need you more than ever.

In my Starfleet days I witnessed the terrible consequences of altering a timeline, due to some travel to the past that changed something crucial. I have experienced the existence of universes and dimensions, different, or even opposite to mine. I have also known of reports from other crews about the most remarkable encounters with myriads of parallel universes.

Your shipmates are different and nevertheless the same ones I knew. In many ways, your Enterprise and mine are the same one. At first, I thought it was time's stream way of attempting to mend itself. I know, it is illogical, since time is not a sentient being, therefore it cannot have any personal purpose.

On the other hand, if I had just traveled back in time, if you and I are the same one, how is it that my existence was not erased when Nero destroyed Vulcan and changed your life? How is it that I have all the memories of my own life and not yours?

I think by now we are both aware that what happened here was not just a travel back in time, but also a travel between parallel universes. If you had examined my quantum signature, you would have detected I come from another place.

From the beginning of civilizations, starting with philosophers like the pre-socratic and the fe-Surakik, many scientists have attempted to explain the way a universe sustains itself. The efforts of Kazanga and Sitar of Vulcan were directed to ascertain how parallel universes develop and coexist in the space-time continuum. In their studies they addressed the problem of these universes' origin and how they become different from each other.

What has caught my attention it is not the differences anymore, but the similarities. We are different, but how is it that we are also the same? What holds all these universes developing in parallel ways? Is it there some kind of physical element communicating all of them? To what extent? Did Sarek and Amanda met and had a son called Spock, in each and every timeline or universe?

Maybe there are many Spocks in many universes, facing different circumstances and making different choices, taking different paths, loving and being loved by different beings. Maybe that is the way the Universe explores all its possibilities, so at the end of all time, if such an end is meant to be, there will be nothing left unused.

I know, the Universe it is not a sentient being either.

I see all Spocks that ever existed and are going to exist, looking for answers to so many different questions. Maybe that is what we, you and me, are meant to be.

The universe I came from should still exist.

I have been working toward an understanding of the way parallel universes remain parallel, or, better said, stay communicated. So far, I have been unable to complete a working hypothesis for it. As we have observed, an apparent travel back in time, causing a deep alteration in the timeline, it is not just that, but it is also the creation of an alternate timeline, or, in other words, a travel to - and the creation of - an alternate universe with its own timeline, simultaneously, which stays in contact with the original one, by the means of… what?

It should be a constant among all universes, something both variable and at the same time absolutely invariable, setting a kind of harmony for all of them and harnessing entropy. I am endeavoring to determine it so the equation be complete and functional. I need the exact concept before translating it into mathematical language. How do you define and call something of which you have experienced the effects but you do not know what it is?

After gathering data from all currently available sources and my memories, I have made the calculations and compared all the options. Through the results, I have deduced its existence and action, but not its nature. Sensors do not register it. Maybe it is a kind of energy field too subtle for them, or we have not yet devised the right instrument to measure it. It can be necessary to search for it until a discovery happens as it was with cosmic microwave background or gravitational waves. Perhaps it has been always right in front of us like electro-magnetic radiation.

Chord. Flux. Relation. Resonance.

I keep adding things as they come to my mind. It might still work, although the missing constant's definition eludes me. It must be something physical, a kind of vibratory energy, able to go through the limits of time and dimensions, keeping its own order and equalizing itself as much as it orders and equalizes every universe by which it travels.

A name. A word.

Humility, from the ancient Latin humus, land, soil, dirt. "Human", has the same root. Words have deep roots. Arrow of time.

Sybok's laughter. Whistling wind. Rocking sea waves. Crackling fire. Whales.

Nostalgia, from the ancient Greek nostós, a homecoming, and algós, pain. The pain for the home you want to come back. There is no Vulcan word for such a concept. Mount Seleya gleaming at sunrise.

"To be" in Spanish, is split in two different verbs: ser, for permanent things, like being a scientist, and estar, for non-permanent things, like being in a certain place. Interestingly, for the condition of being alive or dead, estar is the usual verb. A quantum concept from an old language?

Rhytm. Strings. Synchrony.

Katra, Soul, Essence, traditional names for some kind of energy. Katra exists in Vulcan experience. Soul in Humans is unproven. Essence, energy of thought capable of existing after the biological body is dead, has been found in highly evolved species. There are also living species consisting of pure thought, pure energy. Is this kind of energy also able to go from one universe to another one?

Humans understand death as a travel, a reunion with lost loved ones, or simple nonexistence. Nonexistence is not to be feared.

For many years I strived to honor my father and the Vulcan way. Later, I found my own path. This time, I wish to honor my mother and die a Human death. No ritual, no certainty, just leap into the unknown and hope for the best. I will not leave my katra behind. Do not grieve. My life was not wasted. And you know that my memories belong to a different place. Here, they would only serve to cause confusion.

A vision beyond logic, can it be successfully included in a differential equation? Would it be merely an expression of wishful thinking, therefore non-scientific and utterly foolish? Or just utterly human?

Incomplete equation. Experimental method.

Peace. No regrets. Still curious.

"Vulcan Cultural Heritage Project" archive, file S1E24. It seems I have made a mistake. I believed that I had recorded an ancient herbal medicinal potion, but now, when I think of it, I remember drinking it in a warm and humid night, under a bright full moon. And I cannot trace where this memory comes from. If you ever find the facts, please make any necessary correction."

Spock made a mental note of the drink, of which he had no idea whatsoever. Then, he checked the "Field Research Reports" archive for the creatures the Romulan student had mentioned. It was easy. There was a very detailed table of contents and indexes inside the indexes.

"Kingdom: Animalia.
Species BM1931-DF2015.
Phylum: Arthropoda.
Class: Insecta.
Order: Apodiformes.
Suborder: Hexaptera.
Superfamily, Family, Subfamilies: Pending further phylogenetic studies.
Body size: 12 cm. long by 3 cm. circumference (average).
Color: Golden, vertically striped in black the males, plain golden the females.
Eyes: Composed, covering two-thirds of the head, red.
Wings: 15 cm. long by 1 cm. wide, translucent with a blue tinge. Remarkably stable flight at normal hovering.
Legs size: 2 cm. long.
They feed mostly on the vine Vegetable Species TC1964-ID2013's flowers nectar. Have a tendency to swarm as they search for nutrition sources.
The male of the species produces a distinctive flute like call, each individual a specific note, ranging from Bb3 up to G6. The resulting combined sound is in between the Deltan gourd mouth organ and the Terran wind harp.
Proposed scientific name: Vulcan, Amanda uralausu. Latin, Amanda cantor.
Proposed common name: Vulcan, Salan-rarav. Standard, Windsong."

Spock leaned back in his seat. Yes, Mother waking him up with her singing, must also be a constant in every universe.

He turned off the screen, and left his quarters for the observation deck. The only lighting in there was the light of the stars. He believed he needed to meditate. Actually, he just wanted to think.

Yes, they were different, and completely other. And yes, against all logic, he was grieving and felt very much like crying. But, above all, he was grateful for having had the unique opportunity of knowing that other being, that other version of himself, with so many qualities to which he aspired. He knew he was becoming a better man because of that. Now he knew he didn't need to cut a piece of himself off each time he made a choice. And now he also knew that what Humans call hope. Some day he also could leave the sorrow for everything that was lost behind, find comfort, and marvel in front of new inventions and discoveries again. Some day he might have a child, if not from his body, from his mind and heart, to whom he could tell all of these things.

So much to learn, so much to consider. Read Byron. Talk to Nyota. Read Shakespeare. Talk to Jim. Read Camus again. The next time McCoy invited him to have a drink, with a side dish of chatter, at least pause before refusing. He would find peace, eventually. He kept staring at the stars. At that universe, his own universe, so full of possibilities.

LLAP.