"How do you know you won't like it if you've never tried it?" Jim's tones were dulcet as he glanced up at Spock almost shyly through his eyelashes – a trick that had proven effective once or twice in the past.

Still in uniform, standing with hands clasped behind his back, Vulcan dignity fully in place, Spock calmly regarded Kirk. His dark gaze took in Jim's mostly-nude body, seated on the edge of the captain's bed; the length of brightrope in the captain's hands; the additional coils stacked and ready on the headboard section; Jim's hopeful expression, which did not even try to conceal his excitement nor his longing.

For the thousandth time, Jim thanked his lucky stars for this interesting side effect of Vulcan emotional control. There was no intimate act, no matter how strange or embarrassing by human standards, that he could propose to his stoic first officer that Spock would not be perfectly willing to do to him – even unto binding his captain hand and foot, and tormenting him, sometimes until Jim literally begged for release. Outside the madness of pon farr, Spock's people regarded sex as they did everything else. Your job was to do your best to fulfill your partner's desires, and they yours.

But for once, Kirk was fully prepared to be disappointed. He had never even brought up the idea of tying up Spock before. Always before, the Vulcan had bound him… or held him down…. coldly, impassively watching him struggle – he steered his thoughts in another direction.

If Jim was honest with himself, he didn't entirely know what the hell had gotten into him that he wanted to bind his loyal, logical first officer. Why render his partner helpless when Spock was already under his command every day?

He only knew that some tiny inner voice whispered to him, you never know… it could be fun.

If he could convince the Vulcan to try it at all.

Spock's eyebrow raised ever so slightly, as if showing the beginnings of irritation before his reaction could be schooled. "Captain," he replied evenly, "there are many things that I do not have to try to know I would find them unpleasant." A pause. "Or at the very least, ungratifying."

"You've got a point there," Kirk chuckled. He visibly relaxed, tossing the brightrope onto the headboard with the other coils. He lay back on the bed, hands behind his head, still smiling. Staring at the ceiling, he reflected, "I'll never forget the first time I worked up the courage to ask a girl to tie me up. It was more than unpleasant; it was terrifying." Turning his head to one side, he boldly, deliberately met Spock's cool gaze. "The very thought of being at someone else's mercy. Unable to free myself."

Spock's head inclined just a bit. His gaze shifted away from Jim's, focusing on the wall. He was silent.

Oh, how Jim knew this man. He almost had him….

Kirk opened his mouth to say something else – he had no idea what – when he was uncharacteristically interrupted by Spock.

"Captain." A breath. "Are you implying that I am not in mastery of my own emotions? Including fear?"

"No, no, no," and now Kirk was laughing outright. "We both know that's absurd. And anyway, I'm forgetting that strength of yours. This brightrope wouldn't stand a chance."

Not that he ever actually forgot Spock's strength…. The almost-rib-cracking embraces, the ridiculous stamina, the piston-perfect intensity of his thrusts, the –

"Then let us try it." Without any actual change in facial expression, Spock's eyes met Kirk's again in a clear challenge. "Unless you have any objection to losing some of your rope."

"Spock, I can get more," Kirk chortled. "It's not like this stuff is rare."

"No." And here Spock's wry humor glimmered through. "Not rare. In fact, entirely pedestrian. However, this particular use of it is a bit unusual."

"The cargo bays won't miss it."

"They have not have so far."

Jim sat up, casting off the lackadaisical attitude he had affected. Slowly, never taking his eyes from Spock's, he reached over for the recently-abandoned brightrope. Plying it gently with both hands, he stood, facing his first officer.

For an eternity, neither of them moved.

The next thing Jim knew, he was flying backward. His bones jarred against the wall as Spock slammed into him, one knee in his captain's belly, pushing the very air from his body. Jim was dimly aware that both his wrists were pinned above his head. He gasped for breath and found Spock's mouth grinding painfully onto his own, Spock exhaling directly into his lungs. The Vulcan's breath was sweet but very hot; Kirk fought off panic until he remembered he could still breathe through his nose.

At that first shuddery inhale, Spock calmly backed off his captain just slightly – although he did not release his wrists. To underscore Jim's present helplessness, he effortlessly kept the captain trapped with one burning hand while with the other he caressed the side of Jim's face.

His own expression had never changed.

Jim continued to gasp for breath, the rush of panic still on the edge of taking him over, feeling himself transformed, knowing Spock was still as calm as ever. Damn his Vulcan precision, his ingenuity, his turning their sex life into one giant experiment… Jim struggled to get free and discovered his legs entangled by Spock's, in addition to his arms still being compromised. He was completely pinned, completely vulnerable. There was no way he could escape.

He pushed and pulled for a few more moments and then went limp, still panting. He resented the hell out of Spock, even as his erection strained at his briefs. The very idea that someone could do this to him…

That he wanted someone to do this to him…

His eyes narrowed, finally meeting Spock's again. "Let me up."

The Vulcan did not move.

"Spock," and now exasperation crept into his voice. "I thought you just agreed to let me do things to you. For once."

At that, he was released. He traversed the few steps to his bed and all but flopped down, automatically rubbing his wrists, though it was his diaphragm that had taken the worst pounding.

So far.

He tried to push the thought out of his head.

The rope had landed on the floor. Without a word, Spock retrieved it and handed it over. Kirk slowly moved to the center of the bed and sat crosslegged, breathing still a little ragged. Spock watched him, saying nothing, waiting to see what his captain would do.

"Spock." Jim hesitated. "This is going to be easiest if you… kneel."

Spock's head tilted just slightly. "Captain?"

"Uh… here. Sit here. Back to me. Kneeling, legs folded under you." Kirk was puzzled by Spock's seeming ignorance until he remembered that for this sort of bondage, Spock usually had him stand up to place the rope. Stand up… probably just so the Vulcan could throw him back down and… Again, Kirk mastered his thoughts. He was not going to do anything like that to Spock. Just tie him. That was it.

Spock obeyed, kneeling in front of Jim. However, Jim couldn't help noticing that Spock's hands were still in front of him, palms resting on his thighs, even though the Vulcan had to know that the ultimate goal was hands bound behind his back. He was not going to make this easy.

"Arms back, please," Jim ordered quietly.

Spock complied.

Feeling clumsy, hands almost shaking (from the recent body slam or from nerves, he wasn't sure), Kirk bound the Vulcan's hands and wrists together with an entire coil of brightrope, looping it into makeshift cuffs around each wrist so the tension would be evenly distributed. He deliberately pulled the rope tighter than he would on a human, erasing any leverage Spock might otherwise gain.

He had a feeling it would not be on Spock for long. And besides, his emergency cutter was right there on the headboard, as usual.

"All done." He dropped his hands.

Spock flexed.

Immediately, the outsides of the rope between his wrists stretched just slightly, then frayed open as the individual strands broke. Without appearing to strain, Spock separated his hands just a bit more and the rope's outer layers completely splintered, revealing the highly-stressed brightron cores.

Another moment, and the cores were broken too.

Spock made as if to return his hands to their original position on his thighs, then stopped. He remained quiet, hands behind his back. He had no idea what his captain's response would be to his breaking free so quickly.

To his relief, Jim chuckled as he removed the fragments from his first officer's wrists. "Spock, you've got to see this."

The Vulcan shifted around to face Jim, returning his hands to his thighs. He beheld the frayed and broken brightrope without so much as a raised eyebrow. "I am glad you approve, Captain."

Jim's chuckles turned to outright laughter. He rocked back and forth on the bed.

Spock regarded him evenly. "May I ask why broken brightrope provides you with such amusement?"

Jim merely shook his head, continuing to laugh.

Spock waited quietly for his hilarity to fade.

Still chuckling, Jim reached under the bed. Facing Spock once more, he brought out a familiar contraption and placed it into the Vulcan's hands.

The manacles – or "irons", as they were known colloquially – were used when transporting Starfleet prisoners. This pair looked slightly different from the ones Spock was used to seeing; how, he could not say. He only had one thought, which uncharacteristically drove everything else from his mind: the manacles were designed for a variety of humanoid species. Unlike the rope, their durability would be far greater than that needed to hold a human.

They were easily strong enough to imprison a Vulcan.

Spock regarded the device uneasily. For no reason he could name, the manacles had suddenly taken on a sinister quality. A tiny, corrosive tendril of fear began to eat its way through his carefully-forged shield of emotional control. Suppose Jim wouldn't let him out? Suppose there was some emergency? How much would he be limited by losing the use of his hands?

Logic, implacable logic, reasserted itself. This was a game, he told himself. Just a game, something humans did for fun, for emotional fulfillment. Jim respected him. He would not attempt to humiliate Spock by keeping him locked up... useless, undignified….

Jim would especially never laugh at him while he was helpless.

Would he?

Spock realized he had spent several long moments staring downward, lost in thought. He shifted his gaze, meeting Jim's eyes again. He read curiosity and concern.

Jim drew breath to speak, but Spock was faster.

"Captain," he intoned, "go ahead."

Kirk's eyes narrowed. "Go ahead and what?"

He was going to make Spock say the words out loud. Fine. As always, Spock would play along.

"Place the manacles on me. I would like to feel…" he paused again. A human expression only. Feelings did not apply. "To know."

To know if there is anything to fear at all. I will never know if I don't try.

He watched impassively as Jim fastened the manacles around his wrists. Tested their tightness.

Clicked the locks shut.

And suddenly, impassivity was completely a thing of the past.

His hands. The hands that he performed his work with every day, that he ate with, washed with, played the lute with. The hands that Jim worshipped, even when they slapped him, choked him, twisted his flesh, caused him unspeakable pain. The hands that soothed, held and caressed his lover when their games were done.

Bound. No escape.

Intellectually, he should have recalled that he could easily function while in manacles. His hands were in front of him, not behind. He still had full use of his fingers – not to mention the rest of his body. He was completely mobile; he could even defend himself if need be.

But his mighty intellect was curiously suspended. In that moment he was utterly trapped; utterly useless. He could not bear to look at Jim. He imagined how silly he must appear, head hanging low, manacled like a common criminal. Like someone being punished.

Such indignity.

The shame and the panic hit all at once, like a roaring tornado, completely overrunning his emotional shield, threatening to destroy all control.

Control…

I am in control of my emotions…. I am in –

"Spock?"

He still did not look up. "Captain?" He managed to keep his voice even.

"Spock, are you all right?"

"I…" He fell silent. He could not bear to admit the truth to Jim. But Vulcans didn't lie.

"Spock?" He detected a note of real concern in his captain's voice. "Spock, what's going on?" When his first officer still did not reply, Kirk demanded, "Spock, talk to me."

The command rebooted Spock's Starfleet training. He struggled with all his might to obey, to find his voice, to answer the question.

"Captain," he all but whispered, "I cannot escape."

Impulsively, Jim grabbed Spock's fingers and held on. The human-cool touch startled Spock for a moment. With his emotional shield compromised, he could feel – unintentionally – his captain's concern, his worry which was rapidly turning into deep unease.

"That's the idea," Kirk replied lightly. Through the ineffective attempt at humor, Spock felt the captain struggling to find the words to reassure him; felt his confusion over Spock's strange reaction.

Spock wanted to tell Jim that – though he was so afraid – his mind knew there was no reason to fear; therefore, he would be all right. But speech was too difficult right now. Concentrating, he "pushed" the sentiment into Jim through his fingers, flavored with Spock's own love and longing and contentment to follow Jim's wishes, even when it was inconvenient – yes, even if it meant experiencing fear…

Jim gasped and Spock felt his captain's slower human heart speed up a fraction, that red blood pulsing just a little quicker…

Hands trembling, Jim lifted the manacles and fumbled at the locking mechanism. But Spock gracefully moved the whole apparatus out of reach.

Jim looked at him, his whole face a question mark.

Finally, Spock could meet his captain's eyes again.

Whatever Jim saw there – combined with the emotion Spock had directly transmitted – melted every ounce of hesitation. Ignoring the manacles, he gathered the Vulcan's too-warm, slender body gently but firmly in his arms, stroking his back, carefully winding his fingers in the straight black hair. He did not withdraw even though the closeness of their flesh greatly increased his emotional contact with Spock's heart-pounding fear-fear-useless-fear-helpless-worthless-fear-fear-undignified-hands-trapped-fear. A hot, hot liquid dripped against Jim's chest. He instinctively flinched before it occurred to him he had never felt Spock's tears before.

Jim's erection was a distant memory. He did not enjoy his first officer's distress. More than anything, he wanted to remove those stupid manacles from his beloved's wrists, but he made no attempt. He could also feel the Vulcan's stubbornness, which was stronger than his fear. What Spock was experiencing, he must overcome by himself.

For the hundredth time, Jim wondered at that incredible discipline his first officer subjected himself to every day; the alien concept which translated, loosely, as "passion's-mastery". He still did not understand it, but he knew this much: most Vulcans strove not to purge emotion, but to be in control of it. And it was not simply control for control's sake. That discipline was the way their race had internalized ethics, ensuring that every action was taken with intention and integrity.

That they harmed no one without meaning to.

Harm… unbidden, Jim's mind flashed to the marks Spock sometimes left in his flesh – marks that took days to fade.

At that moment, Jim felt the fear and stress in his lover, as if in himself, reach its peak and slowly begin its descent. Acting on a very human impulse, he shifted Spock's weight, cradling the Vulcan's head in his hands. He carefully guided Spock's tearstained face to his own. Lips met lips; gentle, exploring, wondering at the cool/hot iron/copper juxtaposition of their physiology; careful, like their first time. Jim felt that rapid Vulcan heart speed up even more, felt Spock's passion stampede over his fear. Forgetting he was still in manacles, the Vulcan tried to open his arms, to embrace Jim.

Interestingly, in the split second before the manacles stopped him, Spock thought he felt the hateful device give, just a little. Curiosity bloomed within him. Moving back from Jim slightly, he gave a massive tug at the manacles – not with all his strength, but most of it. Surely, what he felt couldn't be true…

… Except it was. The manacles broke apart like a cheap child's toy, freeing his right wrist entirely and remaining cracked and twisted around his left.

In less than a minute, he was entirely free.

He raised an eyebrow at Jim. "Captain, how – "

"They're not real manacles, Spock," Kirk explained with a small, ironic smile. "They're only used in training exercises. This pair was made to hold humans, not Vulcans. Plus, there's a little secret we keep from the trainees. These have a quick-release in case of some emergency." Kirk looked at the shards of the device that remained. "Well, they had."

Spock was incredulous. How could he have not perceived the quick-release mechanism? Not noticed something was amiss when Kirk was clamping them on? He had never actually been in irons before, true; but he'd handled them. There was no excuse.

He had been bound because he believed himself to be bound. Nothing more.

"Captain," Spock declared, "I perceive we have just discovered that the Vulcan mind, like the human mind, is still the ultimate bondage device."

"Mr. Spock," Kirk replied formally, "I never doubted it. Besides, are you sure you're the best test case? Being half-human and all?"

Spock did not deign to answer him. Instead, he gracefully swept the broken manacles off Kirk's bed and reached toward the headboard.

Five minutes later, Jim was bent almost double over a convenient chair, now entirely nude, the shredded remains of his briefs strewn over the floor – and still within his field of vision, of course. Spock would enjoy knowing he could see them. His arms were bound inextricably behind his back – he struggled and struggled, knowing he couldn't get free, not letting that stop him. He gasped when the hot fingers of his cool, calm, dispassionate lover probed him roughly, slicking him up – he wriggled so at the deliciously stretchy pleasure-pain that the Vulcan fastened an iron hand on his hip and bade him be still. The captain did not obey even when that grip hardened, bruising him, feeling like as if it would crack the bone.

All else was forgotten when Spock entered him, so forcefully – not waiting for this fragile human to become used to the heat, the texture, the size – and proceeded to hammer at his prostate over and over with Vulcan precision. The pain – the pleasure – oh God, he wasn't ready – he let out a single garbled scream – and just like that his first officer withdrew, leaving Jim empty. Spock grabbed Jim's hair and yanked his head back savagely, bringing tears to his eyes. The Vulcan's other hand clamped mercilessly over Jim's mouth as he leaned forward, placing his lips to his captain's ear.

"Be quiet," Spock hissed, and Jim was satisfied to hear a slight quavering in that normally-impassive voice.

At least the pounding had stopped, Jim thought a bit woozily.

But he was not so easily broken. Taking a slow breath through his nose, he waited till Spock removed his hands, then turned his head as far as he could to glare over his shoulder. "Make me."

His first officer's eyes narrowed just slightly. Jim had just time enough for Oh hell I've done it now to flit through his brain before he felt those burning hands dig into the sides of his ribs, the iron strength of Spock's arms effortlessly snatching him up, like a broken doll, and hurling him bodily onto the bed. He landed roughly on his belly, hardening his abdominal muscles just in time to prevent the wind being knocked out of him… again.

Spock gave him no time to recover. With practiced ease, he flipped Jim onto his back, keeping a fist behind his partner's shoulders so that Jim would not land too roughly on his bound wrists. Releasing him again, he caught Jim under both knees and slammed his captain's legs onto his own shoulders… which, of course, left Jim's ass vulnerable once more. Jim drew a deep, shuddery breath and then held it as long as he could when he felt Spock slide inside him once more… aah, God, he felt so violated, so fucking helpless, at the mercy of this magnificent creature who saw fit to take orders from him every damned day…

… in all areas but this.

The Vulcan picked up the rhythm again and – though Kirk clamped his teeth shut and did his damnedest to keep quiet – he groaned, then moaned, then screamed aloud, unable to help himself, feeling like he was being ripped apart but also just on the edge of coming –

"I will make you," Spock growled.

At first, Jim thought Spock had read his mind and was going to make him climax… but no. He was referring to earlier, when Jim had challenged him to "make him" be quiet.

Oh, no –

Without ever missing a thrust, Spock leaned forward and shoved a burning forearm into Jim's mouth. Jim bit down, wanting to taste the hot copper of his first officer's blood, but Spock relentlessly pushed harder and harder until Jim had to let go and just try to bear the pressure, which threatened to break his jaw.

He suffered; he squirmed; his cries were choked to a halt by Spock's fever-hot flesh. He would do anything – anything – for this to stop.

And he never wanted it to end.

He felt the Vulcan's body tense up, his thrusts beginning to slow. Jim braced himself. Spock ripped his arm from Jim's mouth, throwing his own dark head back as he slammed his pelvis forward … spilling his burning seed inside his captain, scalding him…

Claiming Jim as his own.

In that final instant of climax, Spock's mental shields wavered again, then slipped – and Jim gasped from more than the pain. For one insane moment he perceived not just the Vulcan's feelings, but his alien thoughts – and Jim's own identity, as Spock saw it, shocked him to the core.

His captain. Not a bound, helpless wretch to be tormented; not some silly irrational human to play along with because of their shared bond; not a simple object to be used … but something deep and complex, indescribably beautiful, awe-inspiring, someone worthy of his love and his worship – because only with Jim could Spock feel – this.

The next moment, Spock's discipline slipped back into place. The vision faded.

Alone again in his own mind, Jim became uncomfortably aware of his body as well. He ached for his own release and hoped Spock would allow it. But he knew perfectly well that the Vulcan most likely would not.

He was correct.

In contrast to his former force, Spock withdrew from Kirk gracefully. Stretching like a cat, he obtained the small towel he had thoughtfully brought along for cleanup, proffering it to Jim. Jim strove to ignore his own painful, leaking erection and dutifully toweled off first Spock's still-slick hands and pubis, and then his own traumatized ass.

He was almost done when he felt a fire-hot touch under his chin, forcing his face upward. Startled, he raked his gaze up the expanse of pale-green flesh and hard muscle that was his first officer's nude body, his eyes coming to rest on Spock's.

And Spock's eyes were so dark. Though the lighting in Kirk's cabin was only a bit dimmer than normal, the Vulcan's pupils were almost completely dilated. Jim stared into those black, black eyes, beyond captivated. He felt he couldn't move even if he wanted to.

The softest, most subtle expression he had ever seen came over Spock's face. Impulsively, Kirk, reached up and traced the outline of one exquisitely sculpted ear, feeling extra gratified when Spock's eyes drifted closed. He relaxed into his captain's touch.

Thinking of nothing he would like better than to kiss Spock, Kirk leaned forward. But apparently the Vulcan had other ideas.

Spock's eyes snapped open. He deftly removed Jim's hand, placing it by his side. Meeting Jim's eyes again, he pushed Jim down onto his back, gently this time. He smoothly straddled his captain.

Then his teeth fastened over Jim's jugular.

Kirk clenched his jaw shut in preparation for one of Spock's bites, and was surprised to instead feel such exquisite pleasure that he gasped in pure joy. Spock nipped, he licked, he sucked on his captain's cooler flesh, taking secret delight in surprising Jim once again, in Jim's initial fearful reaction transforming into something far greater.

Through a haze of lust, Jim perceived that the Vulcan's hot mouth was gradually moving downward. He felt his first officer's teeth close over a nipple and helplessly bucked upward as Spock sucked and tongued him relentlessly.

Then, for the first time in forever, Jim felt Spock's hand encircle his erection – his touch so incredibly warm that, as always, Jim pulled back instinctively thinking the too-sensitive flesh would be burned, before forcing himself to get used to it. The Vulcan removed his hand long enough to place the palm to Jim's mouth, which the captain licked enthusiastically, causing Spock to suck in a breath and place his now-slick hand back on Jim's aching length.

Though he wished with all his might to draw it out, to fully enjoy each sensation, the combination of Spock's hot mouth fastened over his nipple and his hot hand stroking with unusual gentleness sent Kirk over the edge almost instantly. His entire body arced upward, every nerve sizzling; then he collapsed down, jerking wildly, head thrashing incoherently from side to side. He could not hear his own voice, crying aloud like the tortured, or the damned. His last coherent thought was to wonder whether he was coming, or being electrocuted…

For once, Spock just closed his eyes and savored Jim's screams. It would be over soon enough, and the sound… ah, the sound. Never from Spock would Kirk learn that he carefully and deliberately memorized each one.

Even between captain and first officer, some things were better left unsaid.