A Christmas party. Mr. Spock was not pleased. It was not that he disapproved of parties on principle; nor of Christmas either for that matter. It was merely the simple fact that attending a social gathering of any sort required interacting with humans in a manner not strictly and completely necessary to either their survival or the completion of their repair work. And when you are trying to live in the past without causing disturbance to the future any interaction is unideal, and unnecessary interaction is the height of foolishness. Or so thought Mr. Spock.

Captain Kirk on the other hand, thought that this was taking it just a bit too far. It was only a Christmas party for people who they were working with anyway (well, them and some family). The whole situation was a tricky one, yes, and if they could it avoid entirely, that would be good. But they couldn't. And if he could join work parties, then by golly it wasn't going to hurt if he occasionally joined a dance party. Mr. Spock hadn't had any qualms about the former.

As a matter of fact, Mr. Spock had. But he looked upon it as a necessary evil, and therefore one that must be borne; as carefully as possible.

Well, Kirk certainly wasn't going to order him to stay if he didn't approve. He gave his first-officer perfect leave to spend the evening however he liked. If he wanted to stay with everyone else, well and good. If he preferred to return to the apartment and finish that transistor unit, fine. But Captain Kirk was staying. He had already told Miss Kelior so.

The long and short of it was that Mr. Spock stayed, though his motivations in doing so doubtlessly consisted less of a wish to hang around with a group of loud, ill-educated, terribly dressed, ancient Terrans for the evening than they did of a feeling of duty to keep an eye on the evening's proceedings.

The empty warehouse was not the loveliest of halls. But no matter. It was large and tidy. Miss Kelior had had a young spruce brought in, and it really did look well standing in the corner. She had some games prepared, and a large bowl of punch. She had gotten somebody to bring in a little old piano, somebody had brought a bass, and there was a middle aged flutist. The three musicians were pretty good. They clearly hadn't played together very long and were not a polished band. But they lent that inimitable cheerfulness of live music to the evening. They played primarily a mix of contemporary tunes which Kirk – not being contemporary himself – didn't recognize. But they did play a handful of classics which had outlived the merely contemporary to become familiar to these travelers from distant times.

Kirk was really rather impressed with Edith Kelior; the young lady had energy – and spirit, to insist upon being merry when everything seemed so overwhelmed with gloom. He thought to himself yet again just what a very excellent officer she would have made if she had been born in the right time.

Mr. Spock was standing quietly in a corner, trying to not be at all noticeable. He was failing as thoroughly as he always did. His blue tuque was pulled down low over his eyes in an attempt to not draw attention to his features. He made sure to avoid the children who were playing around the room. He was concerned about impressionable young eyes around his un-Terran features. He wasn't talking with anyone. That would have been non-necessary interaction. And obviously he wasn't about to dance. He could dance. Kirk had occasionally seen him dance very formal dances at proper Starfleet functions. He was partial to the ones with extremely complex geometrical patterns, though generally speaking he would just as soon watch even those. But in any case, Vulcans did not wiggle and boogie patternlessly around the room – at least not when anybody could see them.

Captain Kirk was enjoying the evening far more. He knew well the important precept that it's silly to demand perfection before you start having fun, and he was as good a freestyle dancer as most people, better than a great deal, and he was quite willing to enjoy it. But as the evening wore on, his imagination kept juxtaposing the great hall of the Enterprise onto the old warehouse. With a twinge of homesickness he gave in to the impulse and mentally replaced the dusty, wired and piped ceiling with the gleaming rhenium arches. The stars shone down inbetween them. Out in deep space, not in a star system. With Orion off to starboard and the great bear just visible up towards the bow. He added the golden evening lights to mingle with the cold brilliance of the starlight. The floor was tiled. There were lights and greenery everywhere. The band grew, there was Mr Kroft's vielle, Mr. Spock's lyre, Miss Uhura's harp, Mr. O'Bader's drum, Bones's squeeze-box.

A bit of darkness fell over his picture with the thought of Doctor McCoy. He tried to reassure himself, for the umpteenth time, that the Doctor couldn't have left the wormhole before them. They'd have to pick up some sign of him eventually. He wouldn't worry about it any more tonight, not tonight. It wouldn't help him. They would find him.

He put the Doctor's accordion back in the band. The partiers he interspersed with his own officers in their shining dress uniforms, familiar faces and bright colors. He changed the dance – something different, something orderly, something simple, something Christmasy; Sir Roger de Coverly of great antiquity. It had long been traditional on the Enterprise at Christmastime.

Some way to stop being homesick, Jim. But the real problem, the one that gnawed uncomfortably at him even when he wasn't actually thinking about it, was that the Enterprise didn't exist – not yet. But she would. Eventually. If they didn't really mess something up big time. He shook off the notion and returned to the picture.

Edith Kelior broke away from a group of people and started walking towards him – he had Mr. Chekhov step out of her way. And he watched her walk across his imaginary hall. The picture presented was a beautiful one, it made him catch his breath, but at the same time, the image of the hall itself lost something … He was looking at two irreconcilable things. Edith Kelior not only was not really in the Enterprise's great hall. She couldn't be. Or rather, it could never have her in it. And his picture was left looking a bit impoverished – without her. This drafty, ugly warehouse was graced with something that the Enterprise did not and could not ever have. The Enterprise almost looked lonesome by comparison. And the warehouse took on beauties.

He tossed off the pictures and greeted her. She asked him how he was and he replied with utter truthfulness that he hadn't had so fun an evening in a long time. For a few minutes they spoke of this and that. She pointed out several people he did not know, asked if Mr. Spock was feeling alright this evening. He said that Mr. Spock just wasn't big on merry-making, and she gave him one of those keen glances of hers, which always made him feel as though she was looking right into his very soul. He was sure she saw past his deflection, but she did not press the matter. She spoke of the dancing instead. She had asked Mrs. Nuthatch to play a waltz or two, perhaps later in the evening, but if she had her way, they would dance Sir Roger de Coverly.

Perhaps it was a little careless of him, perhaps but Kirk replied with enthusiastic agreement.

He knew how to dance it? – Well, the answer was yes, so: "Yes." She paused a minute, in a manner of eager internal consultation, and glanced about the room, before turning to him again and asking: "Would you help me try to do it here? It is the simplest of its kind, surely it would not be too hard to introduce." He could hardly say no – well no – he could, if he had to. Did he really have to? He thought, he tried to think, of any way that Sir Roger de Coverly could cause harm. He couldn't. It was a dance. And it was Christmas. So he said: "Yes".

Her face lit up in a smile; such a smile – like no other smile in all the world. She said it was fortunate this dance wasn't as specific to the musical phrases as many dances. There were a few songs the band played that might work okay. – Oh, no, Kirk said, Mr. Spock could play it.

Mr. Spock listened to the plan, with an expression which someone unused to Vulcan faces might have thought merely severe, but which Kirk – who'd had years of practice – knew was an expression of real concern born of deep conscientiousness.

"May I speak with you, Sir."

The air was sharp, crisp, with a thrilling tang of cold, which for the moment at least was not unpleasant.

"Right, you cannot believe that I'm being so foolish as to dance a folk dance at Christmastime and you refuse to have any part in so potentially disastrous an enterprise."

"You misstate my position, Captain. Your and Miss Kelior's plan is a perfectly innocent and sensible one under ordinary circumstances. The circumstances are not ordinary. Let me remind you that we are not supposed to be here at all. We do not know and we can not know the full implications of our being here. We do not know what effects the smallest of our actions may produce. Logically, it is out duty to act as little as possible upon this world which is not ours."

"Spock … Sir Roger de Coverly is already over four hundred years old. Miss Kelior was the one who mentioned it, not me. We won't be doing anything but allowing her to add a little bit of variety to an event that happened anyway. Edith might even have done it without my encouragement."

"You encouraged her?"

"Spock …. I wish I could just choose actions based on what's right and what's practical! But no. 'What's not likely to influence anything.' Which isn't always either right or practical … This isn't even a question of right or wrong or even practical or impractical. It's a purely … light, additional, good thing. If by carelessly agreeing with Edith about the dance she wanted to do I've changed the evening then maybe that's a good thing."

"It may be, Captain. It is possible that the theory of the fourth dimension under which we are operating is incorrect. We may be adding an unnecessary complication to our choices. However, we have no way of absolutely determining the accuracy of any theory and are bound to act with the greatest caution possible. Under these circumstances ignoring this third criteria in decision making is blatant disregard of the first two. And to engage in morally negligent actions is a most illogical and inappropriate manner in which to commemorate the birth of Jesus of Nazareth."

"Morally negligent?" Muffled notes from 'Let It Snow' drifted from the building beside them. Kirk rubbed his hands, which were starting to tingle unpleasantly with the cold. "I know, Spock, I know, it's that … I could go back in there, and tell her I've changed my mind. That we won't help her with the dance. She'll be disappointed. She may try to carry on herself anyway. Either way, our presence has already effected the arrangement of this evening. Shall it be an effect for the better or for the worse? We can't not exist. Our mere presence by itself makes things a little different than they would be otherwise. We can't stop that, we can just minimize our influence, and try to make it a purely positive one. … I truly cannot believe that one different dance at a party can possibly hurt anything. I think going back on what I said to Edith might, and we really aren't doing very well at making no ripples by making big deals out of everything. If you won't play for us Edith can just have Mrs. Nuthatch play Jingle-bell Rock again."

" … Surely not, Sir."

"Well, we're going to do it, whether or not you help us, so it looks like that's what we'll be stuck with – that or something similar."

"… I do not suppose that there is anything that I could say or do which would persuade you to change your mind."

"Well, if you could show me definitive proof that a slight alteration of the dance programme this evening would result in a universe ending paradox …"

"Your point is quite clear without the sarcastic pauses, Captain."

" Then I would have to tell Miss Kelior no. She might just go ahead and try to lead the dance by herself anyhow, now that she's embarked upon the project … to the tune of Jingle-bell Rock. … Of course, I don't believe that dance has ever been danced to that tune so that would be something never done before."

"It seems then that this alteration will take place whether I participate or not."

"If it is an alteration, yes. It certainly will go on. … Come on, Spock. It's Christmas. And we just asked you to play a song, one song."

Mr. Spock stood silently for a moment, presumably weighing possibilities.

"Very well, Sir. In that case I will play Sir Roger de Coverly … if only to avoid an alteration of the traditional pairing of melody and choreography."

"Thank you, Mr. Spock."

Since he had made up his mind, Mr. Spock hesitated no longer. When he was shown to the piano, a small and rather battered old upright, painted a most peculiar shade of maroon, he ran once up and once down the keyboard with his long white fingers, before plunging into that most light-hearted of tunes.

Meanwhile, the energetic Edith Kelior had gathered everybody up and told them of the old English dance she intended to introduced, explaining that it was the famous "dance at Fezziwig's" in Dicken's "Christmas Carol" and told how she had often danced it as a child. "Jim." she said, and she reached for his hand and took him to the top of the room, nearest the music, he on the left, and she on the right, and had everyone who wanted to try the dance divide into couples, and form two long lines leading down from them. She told them a few definitions; that the top of the room meant the side that the music was on, that the couple nearest the top was called the first couple (which at the moment was her and Jim Kirk), and she defined partners, neighbors, and corners. Then she had them walk the dance through; going through the steps without music. They did this several times through, letting different couples get a chance to walk the different parts through before Miss Kelior thought it wise to give Mr. Spock the go ahead and actually start dancing it.

The music changed it from a sort of game or strange exercise, to a dance. One does not often see grown people really skipping, but here they did. They skipped down the center between the rows to spin wildly with their corner at the opposite end, skipped up and down with their partner, before casting off at the top and weaving down through the others to bottom and grasping hands in a sort of 'London bridge; under which all the other couples went. The music was bright and the music was danceable and the music was forgiving, when a mess up happened – as they frequently did – the dance was just picked up again at the beginning of the next phrase. No fussy choreography was this! And Mr. Spock played right along, not allowing the fumbles and not infrequent spells of confusion to distract him from his even tempo. The notes all fell into place exactly as they were supposed to while Edith scurried about with Kirk, sorting out the tangle and putting all the dancers back in the places that they were supposed to be.

After a few rounds, as everyone got more used to the flow of the dance, disasters happened less frequently, and it became less of a big jolly bit of chaos, and more of a dance. Those couples who were not in motion clapped in time with the beat and some stomped their feet, Kirk and Edith included. As they stood across from each other, clapping, and watching the top and bottom couples and laughing she caught his eye, and flashed him a smile, a golden smile, then took his hand as they paraded up to the top of the room with the other couples.

As they reached the top and cast off along the sides, Kirk glanced up towards the band. The bassist had joined in, playing chords. The flutist been persuaded by one of those who'd left during the walk-through to join in with him at the bottom. Mr. Spock had not had the opportunity to touch an instrument in months, and though he sat there stiff and straight of face, Kirk could see he was enjoying himself in spite of himself.

There was not a chance to discuss the issue again during the party, nor immediately after, since they stayed to help clean up. And their walk home was shared, as usual, by Edith, leaving no chance for secret discussions of the possible ramifications of folk dances. Most of the walk was spent in Kirk and Edith singing carols for the sheer fun of it – it was Christmas after all. Mr. Spock did not consider himself a singer. They were not alone till they bid her Goodnight and Merry Christmas at the door to her apartment and went on up to their own. But they said almost nothing during the hours they spent working on that transistor. It was only when the task was completed and the clock struck one that Mr. Spock said that he hoped that any alterations they had caused that night were either so slight that there would be no lasting effects, or that they would be either purely neutral or positive. He hoped.

Kirk didn't say anything. But in spite of the lateness of the night he lay awake, looking out through the window at the gold moon over the roof-tops, and thinking over the halcyon evening. He could not think that they had done ill. And he could not wish it undone.