A/N: I listened repeatedly to the Bee Gees "You Should Be Dancing" and to "Right Said Fred" while writing this so if you really want to get in the mood you can listen to those while reading the dancing scenes.
The room was brimming with Starfleet personnel. The women's uniforms had been replaced by dizzyingly short skirts, midriff tops, slinky dresses, and towering hair. The men, with the exception of Spock who was wearing his usual blue shirt and black trousers, were dressed in looser clothing, mostly consisting of ripped jeans and extravagantly open shirts. A thunderous, syncopated bassline punctuated by a heavy beat pounded through the room, weaving through the bodies undulating in the middle of the room.
"Spock!" Jim Kirk, his golden hair gloriously mussed, hurtled out of the crowd and stopped right in front of Spock. He beamed breathlessly, his skin shining with sweat, and Spock looked at him with a politely enquiring expression.
"Why aren't you dancing?" yelled Jim over the drumbeats.
"Vulcans engage in dancing solely for ceremonial purposes. Furthermore, Vulcan dancing is much more… refined than this." He gestured disdainfully to the figures writhing in the flashing lights. Jim rolled his eyes.
"It's disco dancing, Spock. It's fun. Surely you understand the concept of fun?"
The disco dancing did not look fun to Spock. The music was awful and the moves looked clunky and purposeless. Though disco had started back in the 1970s, crazes of it had inexplicably cropped up once every century or so since then, as if to remind humanity of its mere existence and to drive all reasonable races crazy with its ghastly so-called music. Jim was oddly fond of it, and he had decided that the way to help the crew unwind after its most recent disaster was to hold a disco-themed party. Spock had been vehemently against the idea. It had gone ahead anyway.
"Come on, come dance," wheedled Jim, his voice partially drowned in the surrounding dissonance. He tugged on Spock's arm. Spock stood firm. He was only at this party because Jim had asked him to attend. He had done his part; he would do no more.
"Spoooock!" Jim whined. Spock glared at him, in a way only a Vulcan could glare: never changing his expression but somehow radiating an air of hostility. Jim was undeterred. He stopped pulling on Spock's arm and a mischievous glint flashed in his blue eyes as he straightened up. A cold stone of foreboding settled in Spock's gut.
"Commander Spock," said Jim in his best I-am-the-Captain voice. "I order you to participate in dancing, for the purpose of raising crew morale."
Spock stared. "You cannot force me to dance by ordering me, Jim. That is not within your rights as Captain."
"My rights as Captain include doing everything that's good for my ship and my crew. This party is supposed to de-stress people, Spock, and you just lurking here like the judgmental finger of God isn't helping. So get out there and dance. Captain's orders!"
Spock thought this over. "If my presence is detrimental to the atmosphere of the celebration, then I shall depart. Good night, Captain." He stepped to the side, intending to bypass Kirk on his way out. Jim, however, mirrored his step, blocking his progress.
"No way. You can't leave. Come on, Spock, just one dance. You can leave after, if you still want to."
He looked beseechingly up at Spock, who felt his will bending. The Captain could be very persuasive when he wanted to be… and one dance couldn't be all that bad. Spock looked over at the dancers, considering their movements. The dance moves did not seem to flow together in any deliberate way, nor did there seem to be any goal in mind other than to make oneself look utterly ridiculous. A lieutenant from Engineering danced by, his hips shaking to the beat, his knees loose, and his arms pinwheeling in opposite directions as if he was attempting to wash invisible windows.
"No," said Spock. Jim groaned.
"I'll show you how, it's really easy, and then you can go. Come on, a new song is starting." He pulled Spock into the crowd, where they stood facing each other. The sparse beginning beats tightened into a quick riff and a falsetto voice swept into the song. "Watch me," said Jim. He began moving his body, his elbows and knees swinging with the music, before he suddenly spun with one of his arms still extended, almost hitting Spock who ducked out of the way just in time. A few surrounding dancers weren't so lucky, but they didn't seem to mind. Jim kept moving, though he did take a couple seconds to shoot Spock a look that clearly communicated his desire that Spock start moving instead of standing woodenly in the crowd. Spock mentally swore he would get revenge for this, then he reluctantly began mimicking Jim. He had never danced like this and his body was unused to the movements. He paused, shook his stiff limbs loose, and tried again.
"Oh my God." Christine took Nyota's elbow and shook it. "Are you guys seeing this?" Nyota followed Christine's shocked gaze, and felt her mouth drop open. Gloriana's hand flew to her mouth. Marie had been taking a sip of her drink, but when she saw the object of her girlfriends' shock she began coughing.
Nyota gaped at the dance floor. There was Spock, doing something she had never in a thousand years thought he would do. He was dancing—disco dancing— with the Captain. Spock's moves were perfectly in sync with the music beats, and his body was the least stiff she'd ever seen. His movements were smooth and he somehow made aggressively swinging his hips look suave. Remarkably, his face was perfectly serious. There was something oddly sexy about him as he danced, possibly because Nyota was used to seeing him with ramrod straight limbs and perfect posture. Being surrounded by less graceful human dancers also served to make him seem more impressive.
"We should join them," said Christine. Her eyes were wide and her chest was heaving in her too-tight shirt. Jealousy surged through Nyota.
"Yeah," agreed Gloriana. "He'll never dance like this again so we should take the chance while we can." The three women began moving toward the Captain and the First Officer. Nyota followed, pushing her way to the front of the group so that she would be closest to Spock.
"Good evening, Nyota," said Spock calmly, as if they happened to be passing each other in the hallway after an evening of reading reports.
"Uhura! Ladies!" Kirk grinned at them and wound his arm around Marie. Nyota studiously ignored him and began dancing with Spock, doing her best to shield him from the women who were aggressively trying to dance up against him. It was lucky that so many disco moves doubled as combat moves, she thought as she flung an arm out.
By the time the song had ended, Spock felt strangely tired, as if he had just been sparring. He had not thought that dancing could be such a strenuous activity, but perhaps he had to rethink that opinion. A small army of women seemed to have amassed around him, and it was difficult to push his way through them. A new song was starting up and if Spock didn't escape in time he might be forced to dance some more. Jim slipped into the middle of the crowd of women and flashed Spock a thumbs up, which Spock took as a sign that it was acceptable for him to leave now.
Nyota followed him out of the crowd. "What was that?" she asked as soon as they had escaped the racket of the party. The tips of Spock's ears turned a faint green.
"I was simply doing my duty in raising crew morale," he replied. Nyota blinked.
"I don't follow your logic."
As they walked to his quarters he described what the Captain had said to him. At the door to his cabin he bade her good night, and as the door swished shut behind him Nyota made a mental note to thank Jim Kirk.
Spock's disco dancing, she decided, was a memory she would treasure forever.