Dr. Leonard McCoy snorted as he sat at his desk in sickbay, reading his latest orders. Starfleet Command had ordered that he be temporarily assigned to a Starfleet science vessel, to assist with their research into a new treatment for blood disorders. The kicker was that the science vessel in question was crewed entirely by Vulcans.

The Enterprise had discovered a database of medical knowledge possessed by the Fabrini just a few months before, which had the potential to revolutionize treatment for a number of conditions. Thanks to the Fabrini cure for the fatal blood disorder xenopolycythemia, McCoy was the only person in the Federation who'd survived that disease. The Vulcans had great hopes—in their restrained Vulcan way—that the knowledge the Enterprise had gained from the Fabrini would be just as useful in formulating treatment for a similar blood disorder in Vulcans.

McCoy enjoyed medical research, but he liked the hands-on experience of treating actual patients better. Still, the idea of adapting the treatment that had cured him to save others was tempting, if only he didn't have to spend six months on an all-Vulcan ship to do it. The idea of spending half a year as the only human on a ship with a bunch of pointy-eared walking computers gave him chills ... and not the good kind.

Being one of the captain's best friends did ensure that he always had Kirk's ear. Maybe Jim could get him out of this. McCoy turned off the computer on his desk and made a beeline for the captain's quarters.

He pressed the chime and was admitted readily. Kirk was seated at his own desk, probably reading those very orders that McCoy wanted to talk about; the captain waved him to the chair on the other side of his desk and said, "Looks like you've seen your new orders already. I was just about to come find you, to discuss them."

McCoy glowered at him. "I want to know which nincompoop thought posting me to an all-Vulcan ship would be a good idea!"

Kirk smiled placatingly. "You saw the orders; they come from Admiral Westervliet—the admiral who supervised our handling of the problem with the Fabrini—so he knows what we do about the Fabrini database.

McCoy sighed. "An admiral. I might have been able to talk you out of it, but if this comes down from an admiral..."

Kirk leaned forward in his chair. "Bones, think of the research possibilities! Here's your chance to really dig into that Fabrini knowledge, to find cures for people who have diseases like the one you had."

McCoy frowned. "But why do I have to go to the Salk for that? Spock and Chapel both know at least as much about the Fabrini database as I do; why can't I do the research with them?"

"Of our people, only Spock knows much about Vulcan blood disorders, and several researchers on the Salk are experts on them. Plus, we only have one Vulcan on the ship. When the time comes to test whatever you come up with, the Salk will have plenty of people to donate blood for testing. Surely you can't plan an entire research program on a Vulcan disease with a single Vulcan for your test subject, especially considering that he's a hybrid and may not be typical."

McCoy sighed. "No, you're right; this research should be done on the Salk. But six months! Jim, if I have to spend six months as the only human on an all-Vulcan ship, I might go completely nuts."

Kirk smiled. "I have more faith in you than that. If anyone goes nuts, it'll probably be the crew of the Salk."

"Hrmph," McCoy said, "I can see I'm not gonna get much sympathy out of you."

Kirk shook his head. "It's a great opportunity, Bones, not just for the research but also to broaden your horizons. Vulcans are our staunchest allies, and they can be wonderful people; it's about time you appreciated what they have to offer. I think doing medical research in their company may be just what the doctor ordered."

McCoy glowered at Kirk. "This doctor ordered a case of bourbon to go with me, to keep me some kind of company on a ship full of people who pretend they don't have feelings."

Kirk smiled. "Don't worry, I'll comm you whenever we're in range, and I bet Scotty and Chapel will, too. And look at it this way: maybe you'll understand what Spock has lived with, every single day of the past nineteen years."

McCoy shook his head. "After nineteen years, you'd think he'd be more human."

The annunciator chimed, Kirk said, "Come," and the door slid open as Spock walked into the room.

He nodded at McCoy and said, "My felicitations on your latest research opportunity, Doctor." He pulled up a chair and sat beside McCoy.

McCoy scowled at Spock. "If you think it's such a great opportunity, why don't you go to the Salk, and I'll stay here?" He turned and looked at Kirk. "Come to think of it, why didn't Starfleet order this for Spock instead of me?"

Kirk smiled wryly. "I'm afraid that's my fault. Westervliet made noises about following up the Fabrini knowledge on a science vessel, and I made it clear that I couldn't do without Spock, not for any amount of time. I pointed out that we had fourteen science labs and a full complement of scientific experts here on the Enterprise, so we were fully capable of putting the Fabrini knowledge to good use. I didn't realize that Starfleet was especially interested in a cure for Vulcan blood disorders, or I'd have known we couldn't keep it in-house."

Stung, McCoy frowned at Kirk. "But you didn't tell him you couldn't do without me."

"The admiral didn't mention you! But really, while I, personally, will miss you, I think the Enterprise can limp along with only doctors M'Benga and Sanchez and our stellar nursing team for a few months. We're scheduled to investigate several planets for possible colonization, and we'll be deep into Federation territory, far from both the Klingons and the Romulans." Kirk shrugged. "New planets are never completely safe, but if two doctors and the nursing team can't handle a few scrapes, sprained ankles, and allergies, your training program isn't as good as I think it is."

McCoy sighed. "M'Benga and Sanchez are both excellent, or we wouldn't have 'em here, and Chapel is almost a doctor, herself. But I like feeling settled, damn it; I don't want to change ships."

Kirk smiled. "I'm glad you're so attached to the Enterprise that you don't want to leave her, but it'll only be for six months, and it really will be a great opportunity for you."

McCoy looked at Spock. "Did you just come to gloat over my leaving, or did you have something to say?"

Spock stiffened. "I am acquainted with several of your new colleagues and thought you might find an analysis of their virtues and failings to be useful in becoming acclimated to your new post."

McCoy smiled. "That's nice of you, Spock. Yeah, I would like to know more about the people on the Salk. What can you tell me?"

Spock relaxed slightly. "I am well acquainted with Rumek, the chief science officer, as the two of us attended the same ShiKahrian school and studied the same subjects. He was the second-best Vulcan scientist of our generation, and he had his choice of positions."

McCoy cocked his head to one side. "Who was the best scientist of your generation?"

Spock raised a brow. "I was, Doctor," he said, in a tone of voice implying that this was common knowledge and needed no discussion. "Rumek joined Starfleet not only because of the opportunities it offers for scientific investigation but also because he is a true proponent of IDIC, and he welcomed the opportunity to further his acquaintance with other peoples, especially with humans. Although he accepted a posting to an all-Vulcan vessel, he will be eager to make your acquaintance, Doctor, and to work with you."

McCoy sighed. "I'm guessing that's not gonna be true of all the Vulcans on the Salk."

Spock shook his head. "It will not. I know of no one on that ship who is actively prejudiced against humans, but not all of them are as tolerant of differences as a Starfleet officer should be, any more than all human officers are."

Spock's dark eyes looked slightly sad, and McCoy was reminded that Spock probably had personal experience with this, from his time growing up on Vulcan as a known hybrid.

Spock went on, "Although it shames them both as Vulcans and as Starfleet officers, first officer Golvon and scientist V'Lor are among the less open-minded personnel. However, you will find that Captain Jaarvik and scientists Sulek and T'Bel have the attitudes that one would wish for in Starfleet officers. And you will find that although Sulek and T'Bel are not of Rumek's caliber, they are very able scientists, nonetheless."

McCoy smiled. "Thank you, Spock. I appreciate knowing who to be extra careful with and who I can relax around."

Spock inclined his head. "I wish your time among my people to be a pleasant one. You should also take these." He held out two small rubber bands.

McCoy took the bands and looked at them curiously; they were so small and so nearly the same color as his hands as to be almost invisible while he was holding them. He looked back up at Spock. "Little rubber bands? Why on earth would I need little rubber bands?"

Spock's eyes crinkled at the corners, which probably meant something if you could read a Vulcan's minute facial expressions. "You will not need them on Earth, Doctor, but you will on the Salk. When you beam aboard, protocol dictates that you be formally welcomed by several senior officers, all of whom will give you the Vulcan salute. They will expect it from you in return, and failure to perform it would be seen as an insult, as a deliberate rejection of Vulcan customs. I am aware that you find the necessary gesture insuperably difficult, but if you band your fingers into position before beaming aboard, you should be able to avoid a social misstep during your first moment aboard the ship."

McCoy looked at Spock, unsure how to react to this. "Are you doing this to help me, or are you doing this so I don't embarrass you?" As Spock opened his mouth to reply, the doctor added, "And don't tell me that Vulcans don't get embarrassed, because I don't believe it."

Spock stiffened. "Make of my motives what you will, Doctor; I have done what I came here to do." He stood and swept from the room.

Kirk sighed. "He was trying to be nice to you, you know. You could have met him halfway."

McCoy frowned. "I can't read Spock the way you can, so I didn't know what he was trying to do."

Kirk looked annoyed. "Then your time on the Salk will be well spent, won't it?"

Feeling resentful, McCoy stood up. "Well, I don't have time to dawdle; I've got to order my research equipment to be delivered to the Salk, pack my personal stuff, and leave instructions for M'Benga."

#

The evening before McCoy left, Christine Chapel and the rest of the nursing team threw him a going-away party in Main Rec. Most of the crew was there, and McCoy was touched by how many people had turned out to see him off.

Uhura—accompanied by Spock on his lute—serenaded him with a song she had composed for the occasion, Chapel had baked an enormous cake that was enjoyed by one and all, and several of his friends even brought small gifts, most of them of the liquid variety.

Then the party quieted down for a moment, and the entire room watched as an orderly and two nurses put on a farcical skit that purported to show McCoy's first few days on the Salk. The end of the skit showed the doctor frothing at the mouth as Vulcan withdrew from the Federation in high dudgeon. The only people not laughing by the end were he and Spock. Of course, Spock never laughed, but McCoy didn't see anything funny in the skit. He supposed it was a lot easier to laugh if you got to stay on the Enterprise.

McCoy had expected to put up with a lot of ribbing from his friends during the party; what he hadn't expected was that so many people would take him aside to offer advice.

Scotty brought him a drink and said, "Ye keep complainin', but is six months on a Vulcan ship really that high a price to pay for yer life? Ye weren't just a mite sick with that disease; ye were dying, mon."

McCoy grimaced. "Who says I should have to pay any price? The treatment that cured me came from the Fabrini, after all."

Scotty looked stern. "The basic knowledge came from the Fabrini, but didn't I hear that yon Vulcan spent three weeks in the lab without eating or sleeping while he worked out how to adapt the Fabrini treatment to the human body? Or didn't anybody tell ya that?"

McCoy blinked. "No, I didn't know that. Huh. You think maybe he has a heart after all?"

Scotty pursed his lips disapprovingly. "Spock has a heart the same way you have a brain: neither of you always uses 'em when other people want you to, but you do have 'em, and good ones, too." He frowned at McCoy, then left to refill his glass at the bar.

After Scotty had been swallowed up by the crowd, McCoy was still contemplating what the Scotsman had said when Uhura found him and drew him aside. She smiled warmly at him and told him how much they would all miss him, then switched gears on him. "And if you'll listen to the communications officer for a minute and not just the friend, I have some things to tell you."

McCoy had been hoping to do without any more well-meaning advice from people who got to stay on the Enterprise, but he could never say no to Uhura. "What is it?" he asked gruffly.

"Captain Kirk runs a tight ship in many ways, but he lets his senior officers speak more freely than many captains do and a LOT more freely than would be considered normal on a Vulcan ship. You've gotten into certain ... habits ... of speaking that we all understand, here on the Enterprise, but if you keep those habits on the Salk, you could end up in the brig."

McCoy laughed sourly. "The brig might be the best place for me, because then I wouldn't try to strangle anybody."

Uhura pointed a finger at him. "And that's the kind of thing I mean. You can say that here, and everybody knows you're joking, but most Vulcans don't have Spock's sense of humor or his patience with human foibles. Say that kind of thing on the Salk, and they'll think you're insane, and I don't mean Spock's tolerant 'oh, those crazy humans' attitude, I mean literally insane."

McCoy goggled at her. "You think Spock is PATIENT with human foibles?"

Uhura frowned at him. "Way more patient than you are with Vulcan foibles. And just think ... he's served on this ship for fifteen years and was at the Academy for four years before that. Could you take nineteen years among Vulcans? You're not sure you can even stand six months!"

"Nineteen years," he repeated to himself, trying to wrap his mind around what such a length of time as the sole human on a Vulcan ship might do to his soul. Then the music changed to dance music, Nurse Kwan came and asked him to dance, and he lost himself in the music and movement for the rest of the night.

#

The next morning, McCoy reported to the transporter room, to be beamed over to the Salk. Only Kirk and Spock were there to see him off, and the captain explained that half the ship had wanted to be there, but the transporter room couldn't hold them all. Kirk had found it easier to prohibit non-essential personnel from the transporter room entirely than to draw a line between who'd be allowed in and who wouldn't.

Kirk looked at McCoy. "The captain has one last order for you, and then the friend wants to say good-bye."

McCoy chuckled. "Okay, put on your captain's hat and say what you have to."

Kirk regarded him seriously. "You've been focusing on your individual reaction to your new orders, and I've let you do that, so that you'd have time to adjust to them. But now that you're about to leave, I also want you to remember that you're not just going to the Salk as Leonard H. McCoy, you're not just going to the Salk as a human on a Vulcan-crewed ship, you're also going to the Salk as a representative of the Enterprise. And as always, I expect the very best from Enterprise crew, on this venture as on all others. And I'm not just talking about your research skills, which I know you'll exercise to the fullest, but about your attitude and your willingness to conform to local custom."

Kirk gave McCoy his sternest captain's look. "I don't want the word 'hobgoblin' to cross your lips once you leave this ship. Don't compare any of the Vulcans to computers, and don't mention their ears. Talk about green blood only in the context of your research into Vulcan blood disorders." Kirk relaxed a bit and smiled. "Make me proud, Bones."

McCoy scowled. "Why should I conform to their customs? I'm not a Vulcan!"

Spock spoke up. "And yet you regularly exhort me to conform to human customs because I serve on a predominantly human ship." He tilted his head to one side as he regarded McCoy. "I expect illogic from you, Doctor, but not hypocrisy."

McCoy swallowed. "I guess ... I guess I never thought of it that way before." He looked at Kirk. "I'll try, Jim. I will try."

Kirk smiled. "That's all I ask, Bones, is that you give it your best shot. I know if you're really trying, your best shot will be a good one."

McCoy looked dubious for a moment, then his expression firmed, and he nodded.

Kirk said, "And now for the friend." He wrapped his arms around the doctor and gave him a quick hug, then stepped back. "I hope you have a good time delving into the Fabrini medical research, and I hope you make lots of friends on the Salk. I'll miss you, Bones, more than I can say."

McCoy nodded. "I'll miss you, too. It's gonna be a long six months."

Spock raised an eyebrow. "I believe you will find, when adjusting to life among strangers, that work can be an antidote to loneliness and can also provide a bridge across our differing cultures."

McCoy looked curiously at Spock. "I guess you'd know about that, wouldn't you? I'll bear that in mind."

Spock raised his hand in the Vulcan salute. "Live long, Doctor, and prosper."

McCoy put the tiny rubber bands around his fingers, which forced them into the right position, then raised his hand in the Vulcan salute. "Same to you."

The doctor injected himself with a hypo of tri-ox compound so that he'd be able to breathe properly on the Salk, then mounted the steps to the transporter platform. Spock energized the transporter, and McCoy disappeared from the Enterprise in a shower of sparkles, then materialized on the transporter platform of the Salk.

His first sensation was a blast of heat, and he had to brace himself at the onslaught. Of course the Salk was kept at a temperature that would be comfortable for Vulcans; he should have worn his short-sleeved uniform shirt. McCoy immediately began sweating, and he hoped that human sweat didn't smell bad to Vulcans, because he was probably going to be sweating constantly for the next six months.

McCoy was met by three Vulcans, and normally, all he would have seen was three Vulcans. But Spock had told him about the people he would meet, and after that conversation, he'd studied their pictures and service histories in Starfleet records so that he could match names to faces and have some idea of whom he was dealing with.

Captain Jaarvik was a medium-sized Vulcan with short, tightly-curled black hair. His facial expression was perfectly blank, as it often was in Vulcans, and yet McCoy didn't find it as off-putting as he sometimes did, maybe because Spock had told him that Jaarvik was an unusually open-minded Vulcan.

Science officer Rumek would be his supervisor during the next six months and was also the friend that Spock had mentioned. He was the same age as Spock but had a much beefier physique that reminded McCoy of a football player, for all that he doubted Vulcans would be caught dead playing football. He wasn't smiling—McCoy would have been astonished if any of the Vulcans had smiled—but something about his face was more relaxed than the others, and McCoy felt smiled at.

The third Vulcan was T'Bel, a petite Vulcan woman barely five feet tall. Her black hair was cut in a short, spiky style that was probably supposed to be practical and easy to care for, but the result was to make her look adorably elfin, even though her face was so calm and composed as to seem nearly severe.

All three Vulcans raised their hands in the Vulcan salute, and Captain Jaarvik told him to live long and prosper. McCoy raised his own hand, his fingers held in place by the rubber bands, and was glad that Spock's foresight enabled him to return the correct gesture. "Same to you," he said.

Rumek's mouth didn't change shape, but his eyes crinkled in the way that eyes did when people smiled, and McCoy thought the science officer was probably laughing on the inside, at receiving such a colloquial and informal response to his people's usual greeting. Well, McCoy was who he was, and Rumek had better get used to it.

Captain Jaarvik stepped forward and said, "I am Captain Jaarvik, and these are my science officer, Lieutenant Commander Rumek, and our foremost expert in Vulcan blood disorders, Lieutenant T'Bel."

McCoy stepped down from the transporter and smiled. "I guess you know that I'm Dr. Leonard McCoy. I'm usually chief medical officer on the Enterprise, but for the next six months, I suppose I'm one of Rumek's researchers."

Rumek said, "Your equipment has already been delivered. We have set aside a laboratory for your sole use, so that you may work in a room whose life support settings approximate human norms in their temperature and oxygen content."

Was Rumek just being logical, or was he trying to be nice? McCoy couldn't quite tell, but having his own lab that he could set to his own temperature was such a relief that he smiled brightly. "Thanks, Rumek; I appreciate that." He didn't just need a lab, though; he also needed a place to hang his hat. Trust a Vulcan to talk about his lab before talking about his cabin. He looked at Rumek and asked, "And where are my quarters?"

Rumek seemed surprised, in a low-key Vulcan way. "Do you require rest already? Has the day not just begun?"

McCoy laughed and said, "Naw, I don't need to sleep yet; I just thought I'd feel more settled if I knew where I'd be bunking."

All three of the Vulcans took a step back, and McCoy was puzzled for a moment, then realized it was because he'd laughed. They'd accepted his smiles, but he guessed that a laugh must look like a veritable explosion of emotion to people who were used to Vulcan norms. He sighed to himself and thought that it was going to be a very, very long six months.

"'Feel' settled?" Rumek repeated, as he tilted his head to one side and looked curiously at McCoy. He blinked for a moment, then seemed to come to a decision. "If that is what humans require, then I will escort you to your quarters. This way." The beefy Vulcan left the transporter room, and McCoy nodded to the others, then walked quickly to catch up to him.

Rumek showed McCoy both his quarters and the main mess, then escorted him to the laboratory that had been cooled to human temperatures. "I will leave you to unpack and to familiarize yourself with your new surroundings; we will have a meeting of the research team at 1600 hours in the conference room across the hall."

As McCoy oriented himself to his new laboratory, he found the crate of equipment he'd ordered already there. Unfortunately, the large, heavy crate was on the floor in the corner, which would make it difficult to unpack. He managed to slide the crate away from the wall, but he couldn't lift it, and he was cursing whoever had delivered the crate when T'Bel entered the lab.

She watched McCoy fussing with the crate for a moment, then asked, "What is the difficulty?"

"I'm trying to unpack this crate, but it's hard, having it on the floor like this."

T'Bel cocked her head to one side as she looked at him. "Then why do you not put the crate upon the table?"

McCoy spluttered. "I can't pick up a 300-pound crate and put it on the table!"

"Oh." T'Bel picked up the crate and deposited it gently on the table. "Why did you not say so, then?"

McCoy goggled at her, surprised that such a small woman could lift such a heavy weight, and she in her turn had trouble understanding his emotional reaction.

T'Bel looked at McCoy consideringly. "Are all human males this weak, or are you an unusually weak example of your species?"

McCoy growled, "You don't have to insult a man, just because he wasn't born on a heavy-gravity planet!"

T'Bel was momentarily visibly surprised, before she schooled her features into placidity. "I assure you, no insult was intended." She paused and regarded McCoy once more. "But if you believed I offered you insult, I suppose your emotional reaction is then explained. I have heard that humans emote regularly and freely."

McCoy calmed down and looked closely at the Vulcan woman. "I'm sorry, I don't really understand Vulcan attitudes. If a human had called me weak, it would have been an intentional insult. But you ... you just wanted to know, didn't you?"

T'Bel's face softened slightly, in a way that McCoy couldn't quite put his finger on. "Among Vulcans, that is the usual reason for asking a question. Nor are most adult Vulcans likely to offer you deliberate insults." She looked McCoy up and down. "Now that you know that I mean no insult, will you reply to my question?"

McCoy laughed. Somehow, he found Vulcan attitudes easier to take from a pretty young woman than he had from Spock, and he was surprised to find that her straightforward bluntness was actually endearing in a weird way. "Well, my dear, I think you'll find that my strength is about average for human males. Lots of men are stronger than I am, but lots of them are weaker, too."

T'Bel took a step backwards. "I cannot be your dear, for I am betrothed to another."

McCoy held up a hand. "Wait! That's another cultural misunderstanding. I wasn't flirting with you, at least, not with serious intent; it's just the way I normally talk to women."

"What strange customs humans have! Among Vulcans, I am a woman only to my intended; to everyone else, I am a scientist or a Starfleet lieutenant." T'Bel considered him curiously. "Perhaps it would be best if you call me 'Lieutenant,' rather than 'T'Bel.'"

McCoy sighed. "I will if it makes you happy, but really, I didn't mean anything by calling you 'my dear.' As a doctor, I usually have to put human patients at ease, and being friendly helps with that."

"Ah. Another human custom." Her dark eyes smiled at him, even as the rest of her face remained impassive. "I can see that we will learn much from one another, even without the research into blood disorders."

McCoy smiled. "That we will! And please let me know if I say anything that bothers you; I don't know much about Vulcan customs, so you should attribute any mis-steps to ignorance, not malice."

T'Bel looked at him curiously. "You have served on a ship with Commander Spock for nearly three years, have you not? How can you claim ignorance?"

McCoy sighed. "I've been trying to teach Spock about human customs without trying to learn about Vulcan ones." He grimaced. "I realize now that was wrong."

"Admission of fault is the route to learning," T'Bel said, in a tone of voice that suggested this was a proverb among Vulcans. "And now, I have work in Science Lab Four." She turned and left with an abruptness that would have been considered rude in a human, but McCoy didn't really mind. She wasn't a human, after all.

Unpacking his equipment was a lot easier with the crate on the table, and by the time the meeting rolled around, he had everything arranged just the way he liked it. He strolled across the hall to the briefing room, three minutes before the appointed time, and found it empty. He chuckled to himself, imagining all the Vulcans, with their precise time-senses, arriving in a bunch at exactly 16:00. Maybe he'd be able to stand this posting after all, as long as the Vulcans kept unintentionally providing moments of humor.

The Vulcans did arrive all at once and all just seconds before 1600 hours, but they didn't notice anything strange about the amused smile that McCoy gave them, since to their eyes, it was strange but consistent with human norms that he was smiling at all.

Rumek had given his staff a briefing on human customs and mannerisms right before this meeting. Unbeknownst to McCoy, that briefing was enriched by a private communication from Spock to Rumek, telling the science officer about the doctor's known peculiarities. Rumek gathered that McCoy could do nearly anything, short of stripping naked and dancing on the table, and yet Spock had made it clear that McCoy was an excellent medical researcher and a valuable addition to their team. Spock was the best scientist of their generation, and he had worked with this human for nearly three years, so his information was certainly trustworthy, however unlikely it appeared at first. Rumek looked forward to seeing what this emotional human could do.

Rumek called the meeting to order, then gave an admirably concise summary of the facts, problems, and goals involved in adapting the Fabrini cure for xenopolycythemia to Vulcan physiology. He began assigning personnel to tasks and outlining a schedule for the work to be done, then paused and turned to McCoy. "Shifts on the Salk are generally thirty-six hours on, twelve off, with one day of leisure in every ten. I have heard that humans require more rest than such a schedule allows, however."

McCoy had to quash a sinking feeling. It wasn't his fault that he couldn't keep up with the others; he was born into a human body and had no control over how much sleep it needed. It was hard, though, not to feel inferior when he was the sole human in a roomful of Vulcans, all of whom could work longer and harder than he.

Feeling inferior made him angry, and he lashed out. "I'm not made out of steel, like you walking computers! Human beings need eight hours of sleep in every twenty-four hour period, and we need time to relax after work before we can fall asleep. Most human ships have twenty-four hour days, with eight hours on and sixteen hours off, and we work five days out of every seven."

Hell, McCoy thought. Jim asked me not to compare the Vulcans to computers, and here I've broken that rule before I've even been aboard the Salk for a single day. He had to stop reacting so strongly to reminders of Vulcan advantages, because he had a feeling that there'd be a lot of those reminders during the next six months. McCoy rubbed a hand over his face and thought about how to salvage the situation.

Rumek, though, didn't seem at all fazed by his outburst. The Vulcan sent a significant glance around the room—heaven only knew what that meant—and then said, "It was not my intention to denigrate either you or your humanity; I merely wished to know what schedule that humanity requires. If eight hours on and sixteen hours off is customary, then that shall be your schedule."

McCoy slid down slightly in his chair, feeling even worse that Rumek hadn't swatted him down for his outburst but had humored him as if he were a child or a madman. He supposed that to a Vulcan, he looked a lot like a madman ... this must be what Uhura had meant. He'd have to buy her some flowers or something, when he got back to the Enterprise. He straightened up, cleared his throat, and tried to sound conciliatory. "That's fine, Rumek. Thanks, uh, thanks for understanding."

Rumek looked confused by his thanks and replied to the literal content of his words, rather than his meaning. "Are we not all scientists? Understanding is our shared goal."

Once the meeting broke up, McCoy was hungry, and he asked Rumek and T'Bel if they'd have dinner with him. T'Bel eyed him a bit warily and told him that she "did not require nourishment at this time." Rumek, though, considered him silently for a moment and then agreed. McCoy wondered if he were being humored again, then wondered if he would spend all of the next six months wondering what every word and every action meant. He really would go nuts if that happened. Well, they were Vulcans, weren't they? That meant that they were the most straightforward people known to man, and he could just ask, couldn't he? If he didn't mind feeling like a fool, he could just ask.

Deciding to put his new policy into action, McCoy turned to Rumek as they walked to the mess hall. "I don't really understand the social or cultural implications of anything the people here do or say, so I'm gonna just ask questions about every blessed thing, until I get the hang of it all."

The face Rumek turned towards him wasn't smiling, but there was a lightness about the eyes that seemed to imply good humor. "That is an excellent plan, Doctor; I commend you on it."

If Spock had said that to him, McCoy might have thought he was taking some kind of swipe at him, but the doctor was pretty sure Rumek meant exactly what he said—no more and no less. "So I'm glad you're gonna have dinner with me, but I guess I'm wondering if you're actually hungry, if you're being social with me, or if you're keeping an eye on me because I look crazy to Vulcans."

Rumek gave him a glance that McCoy thought might be teasing and said, "Your question contains a faulty assumption."

"Huh? How so?"

Rumek raised an eyebrow. "You assume that it cannot be all three."

McCoy laughed. "Y'know, Rumek, I think I'm gonna like you."

Rumek said, "Vulcans do not declare liking for colleagues, but I believe you will have an ... enlivening ... influence on the Salk."

McCoy laughed again. "Oh, brother, you don't know the half of it."

They reached the mess, and Rumek led the way to the food synthesizers. He stuck a tape in the slot, then removed a bowl that seemed to be a mixture of grains, beans, and vegetables in some kind of sauce, with a side order of fresh fruit.

McCoy said, "I guess your food synthesizers will have a different menu than we have on the Enterprise."

"Until yesterday, only Vulcan dishes were available, but I had several human dishes added in preparation for your arrival. You can eat our food from time to time if any of it interests you, but a steady diet of it would cause you to ingest an excess of copper and an insufficient supply of iron."

"Yeah, I guess it would, at that. So, is there ham and cornbread?" McCoy looked hopeful.

"There is indeed cornbread, because Spock alerted me that you desired to eat it frequently, and also a regional delicacy that he insisted was called 'grits,' though that seems an unlikely term for a food."

McCoy was touched. Spock had told Rumek about cornbread and grits. Between that, the rubber bands, and the lowdown on the Salk's personnel, it seemed as if the pointy-eared computer really had tried to ease McCoy's path ... even though it seemed unlikely that anyone had tried to ease his, when Spock first started serving on all-human ships.

If their positions had been reversed, McCoy thought he probably would have enjoyed rubbing the Vulcan's nose in the abundant humanity of an all-human ship, and in fact, if he thought over his own past behavior, he had done so. Thinking more deeply about it, he had done so practically every chance he got. He was abruptly ashamed of himself. You're a better man than I am, Spock, he thought to himself, but not forever, not if I can help it.

He turned to Rumek. "How about if you get me a bowl of whatever that is you're having, and tonight I'll look over the menu and figure out what I can eat that won't give me copper toxicity?"

Rumek put his tape back in the slot, and the machine produced another bowl. The two men sat and ate their dinners while discussing the Fabrini treatment for blood disorders, how that had been adapted to human physiology, and which of those techniques might help adapt it to Vulcans. McCoy lost himself in the conversation, enjoying delving into the intricacies of medical research, and feeling a measure of peace for the first time since he'd received his new orders.

#

Meanwhile, on the Enterprise...

Spock was seated on a biobed while Dr. Sanchez picked tiny darts out of his skin; at the adjoining biobed, Dr. M'Benga performed the same service for Kirk.

Sanchez removed the darts quickly but carefully. He made no comments about the color of Spock's blood or about the arrangement of his internal organs. He didn't imply that Spock's heart should be in a different location or state that his heartbeat and blood pressure were "wrong" because they fit Vulcan norms instead of human ones. It was surprisingly restful, to simply receive medical care, without receiving slurs about his Vulcanity along with it.

Kirk looked over at Spock, wincing as M'Benga removed a dart that had gone especially deep. "I'm just as glad that McCoy isn't here; he'd have laughed himself sick at the thought that the captain and first officer of the flagship were run out of town by a pack of ninja squirrels with blowguns."

Spock raised an eyebrow. "You are aware that Dr. McCoy will undoubtedly review your medical records when he returns to the ship."

Kirk looked at M'Benga. "You don't have to record..."

M'Benga said, "My notes will indicate treatment for multiple small puncture wounds inflicted by an indigenous species." He smiled at the captain. "As far as I know, 'ninja squirrel' isn't a medical term."

Sanchez finished pulling the darts from Spock, sprayed the small wounds with an antiseptic, and said, "You're all set, Commander." He turned and put the antiseptic away.

Spock sat for a few seconds longer on the biobed, feeling curiously unsettled. Sanchez had treated him with quiet professionalism, making no personal remarks and in fact speaking hardly at all. It was exactly the sort of treatment that a Vulcan physician would have given him, and he told himself that it was far preferable to that which he typically received from Dr. McCoy. Why, then, this sense that his treatment was not complete or that his health did not truly matter to Sanchez? He would have to ponder this during his next meditation session.

#

On the Salk...

Rumek was clearly going out of his way to be kind to McCoy, and Sulek and T'Bel were being very nice, for Vulcans. But even kind Vulcans weren't exactly warm, and McCoy was lonely.

The sickbay staff of the Enterprise was a tightly knit group, as people who go through adversity together often are, and McCoy missed the doctors, nurses, and orderlies he usually worked with. He missed drinking with Scotty, shooting the bull with Jim, and listening to Uhura sing.

Strangest of all, he even found himself missing Spock. When McCoy was surrounded by the hundreds of humans on the Enterprise, Spock looked very Vulcan. Surrounded by the hundreds of Vulcans on the Salk, McCoy realized just how much Spock had adapted to human customs. The teasing banter, the small facial expressions, the willingness to play his lute while Uhura sang, all of it was much more humanized than McCoy had realized. Surrounded by Vulcans, McCoy realized just how much humanity Spock had been giving them all these years and wondered if Spock even remembered how to be a Vulcan among Vulcans anymore. Maybe it was just as well that McCoy had been the one posted to a Vulcan-crewed ship.

McCoy was working quietly in his lab when Sulek came in and asked, "Why did you not reply to my communication?"

McCoy raised his head from the microscope and turned to face the young Vulcan. "What communication? I checked my messages not half an hour ago."

"I called you on the intercom, and you did not answer, yet there is apparently no difficulty in your reaching the intercom."

McCoy blinked. "Huh, that's strange. I've been right here, and I haven't heard a peep out of the intercom. You think I should call Maintenance?"

Sulek said, "I will investigate." He scanned the intercom with a tricorder, then reported, "A scan shows that this intercom is functioning normally."

"The hell it is!" McCoy said. At Sulek's look of incomprehension, he said, "Er, that's a human idiom; it means that I disagree."

Sulek said, "A test is in order, then." He pressed the intercom button, called V'Lor, and asked her to say something to allow him to test McCoy's intercom.

McCoy heard nothing and said, "See? It's broken."

Sulek looked at him strangely for a moment, then got an "aha" look on his face and said, "I comprehend the difficulty. The volume of the intercoms on this ship has been set to a level that is audible but comfortable for Vulcans; that same volume is evidently inaudible to humans."

"Well, could you turn this one up, then?"

"Negative. You will not always be in this room, and it would be illogical to adjust the intercoms on the entire ship to human levels. I suggest that you seek mechanical augmentation of your hearing, instead. I believe ship's stores carries small devices that fit into the ear canal, for times when we must have face-to-face contact with species whose hearing is even better than our own."

McCoy looked aghast. "You want me to wear a hearing aid every day for six months?"

Sulek titled his head to one side as he looked at McCoy. "It is a logical solution. You must be able to hear messages over the intercom, and it would be foolish to suggest that hundreds of Vulcans listen to intercom messages at levels loud enough to be painful, just so that you could forgo hearing augmentation."

McCoy sighed. "Yeah, you're right. Okay, I'll get a hearing aid." Hrmph. Yet another way he got to feel inferior. Well, maybe his hearing was inferior, but that wasn't under his control. His reaction to it was, and he wasn't going to lash out this time; he'd take his inferiority like a man. After all, it's not like Sulek was trying to rub his nose in it or lord it over him. Still, he could use a reminder of the ways that humans were superior, right about now, assuming that there were any.

#

Meanwhile, on the Enterprise...

Lieutenant Uhura was missing. She had beamed down to get samples of the locals' speech, to calibrate the universal translator before the Enterprise contacted them. She'd made her first check-in but hadn't made her second. Kirk wanted to go charging in to rescue her, but the locals weren't supposed to know the Enterprise was here until the time came to speak with them. The locals were a short, dark-skinned people with widely spaced eyes, and Uhura looked enough like one of them to pass for one, but Kirk didn't, Spock didn't, and Scotty didn't.

Spock, of course, had memorized the personnel records of every member of the crew, and he was able to suggest two additional crewmen who could pass for locals. Those crewmen beamed down, and everyone on the bridge held their breaths while they waited.

It was an anxious time for Spock's human shipmates. Kirk never wanted to lose any member of his crew, but he had an especially strong attachment to the people he worked with every day, and the bridge crew seemed tense and edgy, even more so than was usual in such situations.

Spock kept feeling as if something were missing and was chagrined to realize that it was McCoy's ranting. McCoy often expressed the emotions of the entire bridge team, and the tension on the bridge actually seemed higher without his voicing the feelings that the rest of the bridge crew was too professional to speak aloud.

Spock could not, of course, produce an emotional rant on the bridge ... but he did step down into the command well and lay a supportive hand on Kirk's shoulder. Kirk flashed him a grateful glance just as the landing party called in and said that they had recovered Lieutenant Uhura from an old man who'd insisted she was his long-lost granddaughter.

Spock returned to the science station, pondering his new insight. Kirk, Sulu, and the others were able to be as controlled and professional as they were partly because McCoy functioned as a safety valve for their emotions. He wondered if the doctor did it deliberately, knowing that he served that function, or if it were all unconscious. Humans were a fascinating species.

#

On the Salk...

Three months into their research program, progress was stalled. Great progress had been made in adapting the Fabrini treatment for blood disorders to Vulcan physiology, but it had been much easier to adapt the cure from the red-blooded Fabrini to red-blooded humans than it was to adapt it to green-blooded Vulcans. A variation of the drug that had worked so well on McCoy did return Vulcans' green blood cells to normal; unfortunately, it also destroyed their white blood cells, leaving them with a malfunctioning immune system. A different approach was needed.

Rumek called a meeting of the blood disorder research team to discuss the problem. Everyone was clear on what the drug was doing and what it needed to do instead, but all of the obvious approaches to the problem had failed.

Eventually the science officer turned to McCoy. "The rest of us will continue to explore the Fabrini database, but henceforth your sole assignment will be to design a new approach to the problem."

McCoy blinked. "Not that I'm unwilling, but why are you giving this to me?"

Rumek looked at him steadily. "It is well known that humans are prone to flashes of insight, intuition, and creativity that few Vulcans can match. Our current approach no longer produces progress, so now would be an excellent time for some human intuition."

Huh, McCoy thought. Rumek said that humans were better at something in exactly the same tone of voice he used to say that humans were worse at something. It was all just information to Vulcans, without any value judgments being applied. Human strength and hearing are inferior; human insight and creativity are superior. McCoy supposed he didn't have to feel inferior to Vulcans after all. They were better than he was at some things and worse at others, and it only made sense for people to do whatever they were best at. He couldn't think of any human who'd be able to say, "My species stinks at this" with the openness and calm that Rumek showed. Maybe that logic of theirs was good for something ... and so was his own approach.

McCoy sat up straighter in his chair. "I don't make any promises, but I'll do the best I can."

Rumek nodded. "That is all I ask."

McCoy worked feverishly over the next month, partly because he was genuinely interested in the intellectual problem, partly because after his experience with xenopolycythemia, he had a special delight in vanquishing any and all blood disorders, and partly because he wanted to uphold the value of human intuition and creativity. When he finally hit upon an approach that bore fruit, he tested it three times before calling Rumek on the intercom and excitedly inviting him to the lab.

Rumek arrived only a moment later, looking not quite as impassive as usual. McCoy wouldn't say that the Vulcan looked excited, exactly ... but he wouldn't say that he didn't look excited, either. "What have you discovered?" Rumek asked.

"If you add ten cc's of chlorophyll during the second boil, the drug still regularizes the green blood cells but doesn't destroy the leukocytes."

"Chlorophyll!" Rumek looked visibly surprised before he managed to school his face to blankness again. "What led you to test such an unlikely ingredient?"

"Chlorophyll's green, and so is your blood," McCoy said nonchalantly.

Rumek blinked. "That is completely illogical."

McCoy smiled. "It sure is! But the universe isn't always completely logical, either, and that's why you sometimes need a bit of human illogic to figure it out."

Rumek's eyes smiled at him. "Then it is to our advantage that we happen to have a human to furnish the necessary illogic. The assortment of strengths provided by our differences is, in fact, one reason for the existence of the Federation."

McCoy grinned. "Yeah, it sure is." Now that his own contribution had proved to be essential, he was able to be generous about the Vulcans' advantages. "Your team of Vulcans got done in four months what it would have taken a human team a year to do."

"It would have only taken humans eleven point two six months."

McCoy smiled and waved this away. Four months ago, he'd have thought the Vulcan was trying to show him up by doing complex calculations in his head in a split second, but with his new insight, he realized that it was just something Vulcans did.

#

On the Enterprise...

Spock was sitting behind his desk, practicing the lute, when Kirk entered his cabin. The Vulcan pressed a hand to the strings to silence them and looked up at his captain. Kirk seated himself casually on the edge of the desk and asked, "So, have you heard anything from Rumek about McCoy? I'm wondering how the Vulcans are coping with him."

Spock set the lute to one side. "I sent Rumek a message shortly before McCoy departed for the Salk, asking him to be especially forbearing with the doctor, as a favor to me. The day after McCoy arrived, I received a message from Rumek in reply, stating that the favor I would owe him was exceedingly large. Six weeks after McCoy arrived, I received an amended version, which said that the favor would be small. Today I received a new message saying that it was Rumek who owed a favor to me, for giving him an understanding of McCoy that allowed Rumek to work productively with him."

Kirk grinned. "I can't tell you how relieved I am to hear that."

Spock inclined his head. "Indeed. I had feared for the health and sanity of all involved, but McCoy's assignment to the Salk appears to be successful."

#

On the Salk...

The new treatment passed every test they could give it in computer simulations, then every test they could give it in the lab. Finally the day came to test it in a live patient.

D'Par had been fully informed about how experimental the treatment was, but given that her disease would be fatal within a year, she had neither many options nor much to lose. Still, McCoy was impressed by the unflinching honesty with which she faced the facts about her condition and the experimental treatment. A human patient would have expressed considerable anxiety and would have asked multiple times for reassurance. All D'Par said was, "If the treatment is successful, I gain my life, and if it is not, my death advances medical science. That is acceptable." McCoy suspected she was feeling anxious on the inside, but after five months among Vulcans, he no longer expected them to show those feelings.

McCoy administered the hypo with the experimental drug and waited impatiently for it to take effect. An hour passed, then Rumek scanned D'Par with a medical tricorder. There was a slight look of satisfaction on Rumek's face when the Vulcan announced, "Her green blood cell count is back to normal, but her white corpuscles have not been harmed."

McCoy cheered, and the Vulcans all regarded him tolerantly as he did so. He thought maybe he was cheering for all of them, for all of the researchers who'd worked so hard and for all of D'Par's family who'd gathered to witness the test. They couldn't cheer and be Vulcan, but he could cheer, and so he cheered lustily.

#

Finally, the six months were done, and it was time for McCoy to leave the Salk and return to the Enterprise. There was no party on the Salk, no cake, no songs, and no skits. But each of the Vulcan researchers did stop by McCoy's lab or his quarters during the last week of his stay, and each of them did utter some variation of, "Your contributions were valuable, Doctor, and your departure will be a loss for the Salk." McCoy was touched, because he knew that anything the Vulcans said was something they truly meant, and while there was nothing warm in the Vulcans' manner, he found himself warmed by their words nonetheless. He realized that he would miss T'Bel and Sulek and especially Rumek.

On the day he was to leave, Rumek accompanied him to the transporter room and surprised him by saying, "I would take my leave of you in the human way," then reaching for his hand and shaking it.

McCoy covered Rumek's hand with his own and shook it as thoroughly as he knew how. In a heartfelt tone of voice he said, "Live long, Rumek, and prosper!"

McCoy mounted the steps to the Salk's transporter, and within seconds he materialized in the Enterprise's transporter room, where Kirk and Spock were waiting to welcome him. He stepped down from the pad and looked around the room. "It's good to be home!"

A smiling Kirk walked forward and clasped him in a tight hug, then held him at arm's length and looked him over. "Bones! You're a sight for sore eyes."

McCoy grinned. "You, too, Jim. I can't wait to tell you all about it and to hear what's been happening here while I've been away."

Spock stepped forward and said, "I was pleased to hear that your research on the Salk was successful." He paused, then added, "It is gratifying to have you returned to us. I trust you are in good health?"

McCoy turned to Spock. "Spock, I can't thank you enough. I know you did a lot to help my transition to the Salk, and it made a big difference."

Spock clasped his hands behind his back. "It was only logical to ease your transition so that you could function effectively in your research program."

McCoy smiled and shook his head. "We can play it like that if you want to, but I'm onto you now, you big softie. Now that I've spent time with other Vulcans, I realize how much you've been giving us, all these years." He looked at Spock for a long moment, then added, "And the fact is, I've missed you."

Spock's dark eyes smiled at him as the Vulcan said, "Your own absence was most assuredly felt … Bones."

Kirk chuckled. "Bet nobody's called you that for the past six months!"

McCoy mock-sighed and turned a teasing eye on them both. "Humans are so illogical."

Kirk grinned. "If you can stand it, there's a roomful of illogical humans in Main Rec, waiting to welcome you back."

McCoy smiled, pleased. "I'll head straight there!" He left the transporter room, and the door swished closed behind him.

Spock turned to Kirk and tilted his head to one side as he regarded his captain. "When do you intend to tell him that it was you, yourself, who suggested to the admiral that Dr. McCoy be temporarily assigned to an all-Vulcan ship?"

Kirk smiled. "Some truths … are better left unspoken."

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Author's Notes

1. We learned about xenopolycythemia, the Fabrini, and the Fabrini's cures for that disease in the Original Series episode "For the World Is Hollow and I Have Touched the Sky." The current story takes place shortly after the end of the Original Series, which puts it at just about the time when Starfleet Command should have recognized the potential of the Fabrini database and figured out what they wanted to do about it.

2. We know there are Starfleet ships that are crewed entirely by Vulcans, because one is mentioned in "The Immunity Syndrome"—the USS Intrepid. The Vulcan-crewed Starfleet ship in this story is a medical research vessel, so I've named it the USS Salk after Jonas Salk, the discoverer of polio vaccine. There aren't any Vulcan medical researchers mentioned in the Original Series, so I've made do with a human name. It would be Starfleet that named the ship, anyway, not the crew, so a human name is quite possible.

3. Most fans remember Dr. M'Benga from the Original Series episodes "A Private Little War" and "That Which Survives." Dr. Sanchez is mentioned in "That Which Survives" as the doctor who did the autopsy on Ensign Wyatt, but he had no speaking lines and was only a dimly seen shape in the background.

4. ShiKahr is a major city on Vulcan.

5. "IDIC" was a concept introduced in the third-season Original Series episode "Is There In Truth No Beauty?" It's an acronym for the Vulcan concept of "Infinite Diversity in Infinite Combinations," which is usually interpreted to mean that the differences among us are a source of strength and should be celebrated and encouraged, rather than glossed over or suppressed.

6. The xenophobic comments that McCoy makes to Spock have always bothered me. McCoy is too fine of a man and too integral of a TOS character to leave him languishing in his prejudice, so I decided to do something about it. I'm hoping the good doctor is grateful for the cure. :-)

7. I've been asked why this story treats McCoy as if he is the problem, given that Spock spars with McCoy nearly as much as McCoy spars with Spock.

While it's true that Spock spars with McCoy, I think the meaning of his actions is different from the meaning of McCoy's. Think about it: As far as we know, Spock is the only Vulcan on the ship. In fact, as far as we know, Spock is the only non-human on the entire ship, at least until Star Trek: The Animated Series. So when McCoy makes fun of Spock's Vulcan features, he does it from the majority position, as one of 429 humans aboard the ship. When Spock makes fun of McCoy's human features, he does it from the minority position, as the single non-human in a group of 429 humans. Those are very different things.

If the positions in the Spock-and-McCoy sparring feel equal to you, translate them into a real-world context instead. Imagine that McCoy was "teasing" the one black crew member about the color of his skin, while that single black crew member teased the white doctor about the color of his. Those two things would feel very different! Most people would see the black crew member's giving as good as he got as his standing up for himself and would see the white crew member's remarks as racist. And that's the point of view I'm taking for the Spock-McCoy sparring.

Yes, Spock gives as good as he gets most of the time (though he never descends to the level of nastiness McCoy reaches in "The Tholian Web.") But the MEANING of what Spock does is different, because his position on the ship is different. Being a member of a minority is wildly different from being a member of the majority. McCoy has so much human privilege that he doesn't even REALIZE that he has human privilege. But *I* realize it, and in this story, I'm making him realize it, too. :-)

8. Thanks to my husband for looking over a rough draft of this story and to SatisMagic for looking over a later version. By the time I got SatisMagic's comments, it was too close to the contest deadline for me to take full advantage of her suggestions, so she should not be blamed for any infelicities in the story. The suggestions of hers that I was able to implement did make the story stronger, and I'm grateful for the time and attention she gave my little story.

9. I have a chronic illness that leaves me non-functional more days than not. I will try to respond to any comments I receive; unfortunately, my good intentions are frequently thwarted by my poor health. (I do read them all with great attention, even when my health doesn't permit me to reply.)

10. I'm a licensed clinical psychologist in real life. It's a pity that I'll never have the TOS characters as therapy clients, because I've spent an absurd amount of time thinking about them over the years. :-)

11. I don't own Star Trek, because if I did, things would be soooo different!

12. Thanks for reading!

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