Title: Against All Hazards
Fandom: Star Trek: the Original Series (Mirror Universe)
Rating: PG
Characters: Mirror!Kirk, Mirror!Spock
Length: 4198
Content notes: homophobic slur used by a minor character, a short scene of forced public sex
Summary: Spock will endure serving his commander's sexual need as part of the condition to join this confidiential mission. However, Kirk finds his brain much more useful than his body.
Author's notes: I always wanted to do a twist of the instituted sexual free use trope, and this prompt begs out for a tense action/adventure story. I hope that you'll find them fit.

When Spock got off the shuttle and arrived at the military base, at the entrance stood a brown-haired man bending over on a metallic object unfamiliar to Spock. As Spock approached, he noticed the strip the man wore on his clothes. He must be the commander of the team Spock assigned to. The man looked up at Spock, his hazel eyes alert and assessing.

“Lieutenant Spock reported,” Spock said, keeping a stiff posture and impassive expression while he saluted his superior.

"So you're the new guy. I’m your commander Kirk, and my word’s law here." Kirk said, eying him up and down. “To cut thing short, you belong to me for the duration of your assignment here per regulation. If you’re as smart as your file said, you’d better follow them all.”

Spock stiffened his lips. When he volunteered himself for this secret mission, he had accepted that part of his duty would be used sexually by his superior, but Kirk would regret deeply if he thought he could abuse Spock. “I understand, sir.”

"Good. Your file said you graduated from Starfleet Academy with the highest distinction. We had just got our hands on this weapon that no one had figured out how to get it work. Work this out quickly. This’s an order."

An hour later Spock had figured out the basics of its mechanism and Kirk patted his shoulder, paying no attention to Spock's tension. "All right. I know I chose you for a reason.

The Kirk barked at a soldier. “Get your JG to his room."

Spock's assigned quarter was small and sparse, with a bunk bed, a table and a small drawer, and he noticed that there were no signs it was in use by others. He settled up his things and breathed deeply. No matter what problems lay ahead, he would perform beyond all reproach as usual.

The rest of the day Kirk threw him to work after briefing him about the team’s daily operation and his duty. Nothing was mentioned of Spock’s other… personal duty. Kirk also left Spock alone during the night.

Spock frowned. What was Kirk's game?

---

It was worth it to stake his claim on the Vulcan, Kirk thought. When he came across his file, he knew he was just the guy he needed, and whatever Kirk wanted, he got them all.

The Empire sent him and his team to this planet which they nicknamed the dungeon to search and retrieve the alien artefacts they could get their hands on, with a tempting offer. Kirk knew the hidden price tag, but no pain no gain.

He would need a smart science guy though, and this Vulcan was a godsend.

While Kirk didn't bother to remember his file beyond what was useful to him, he had to admit the Vulcan was smart and useful. He had saved Kirk’s beacon several times by detecting and dismantling the traps ahead, while also making good progress on figuring out how the toys they found worked. With this rate, Kirk would get the promised reward and promotion earlier than he expected.

He noticed the Vulcan watching him with guarded eyes. Pretty smart of him for doing so. He wouldn't mind getting a taste of his round tight ass, but he could get a cheap fuck any time he wanted. He didn't need to force anyone to go to bed with him, especially one capable of breaking his neck with one hand.

Jim reckoned that he could give a better fight than the Vulcan expected, but why bothered?

The sunlight was scorching and everyone sweated and cursed, except for the Vulcan who calmly worked on another artefact they retrieved from the dungeon, without even a drop of sweat. But then he came from Vulcan, which was a burning hell itself. One reason why the Empire wisely decided that an alliance was more workable than an outright conquest.

“What’re you doing?” Kirk asked when he walked by the Vulcan’s desk. In Kirk’s opinion, the thing he worked on looked like an Andorian dildo.

The Vulcan replied, “I am investigating the energy signature this device emits. It does not match anything we had discovered so far, but it conforms to what Mardev’s string theory predicts.”

“Multi-dimensional, right? Do you think it’ll come from a single higher dimension or a convergence of energy wave from different sources?” Kirk laughed at the Vulcan’s surprise. “I know my science too. Anyway, what is it good for?"

“Allow me to demonstrate,” the Vulcan said, pointing at a tree forward and pressing a button.

The tree shattered into pieces. But what caught Kirk’s eyes were that the Vulcan disappeared from Kirk’s side and apparated now about half a metre right from his original position.

“The emitted energy distorts the light, making the user appear in a different position from the original as a side effect.”

The Vulcan appeared again in his original position. Kirk stroke his chin. It could be useful for subterfuge purpose if they could figure out the rules behind that. “Can you back engineer this thing?"

“The work is 54.37% done.”

Kirk laughed. Who talks like that? "You have a weird way of saying things.”

“I aim to please.”

Kirk was pleasantly surprised by the Vulcan’s dry sarcasm. Who says Vulcans are all computers?

On an impulse, Kirk asked, “Do you play chess?”

There was a definite lack of entertainment on this backwater planet. Despite the image Kirk carefully cultivated, he thought sex, booze and fight as distraction were overrated, especially during a secret mission like this.

Another surprised glance that disappeared almost as soon as it appeared. “I am a good chess player.”

“All right, no holds barred. Let's see who’s the winner.”

Three games later, Kirk was thrilled that the Vulcan was really good at chess. He laughed when he tipped his king over. “You’re honest about being really good at chess. I played well enough to earn my academy fee.”

“Vulcans are always honest,” the Vulcan said, with a hint of amusement.

Kirk snorted. “When you feel free to, right? By the way, tell me your name again.”

“My name is Spock.”

“All right, Spock. You can call me Kirk when we’re alone.”

The Vulcan - Spock now - hesitated for a moment. “Thank you, Kirk.”

“Another game?" Kirk asked, and Spock set up the board. At least this tour would be more interesting now, Kirk thought.

---

Kirk was boisterous, rough, and impulsive. He was tough with his team, but also drank and party as hell with them. In short, Kirk was a prime example of humanity Sarek had warned him about.

He was also an equal in chess with Spock and asked for a rematch with a good-natured laughter when he lost. He was capable of rapid response and decision making in missions, and there was sound logic beneath his command decision despite his claim otherwise.

He treated Spock the same way as his other team members, demanding the best of them but trusting them to do their job, an attitude rarely found in humans Spock had encountered.

Kirk was an interesting human, and Spock wondered what was more to discover about him.

---

 

The cave ahead was covered with sticky silver spider webs and thick green vines almost covered the whole entrance, made it hard to spot from the outside. Kirk and his team used phasers to burn open a way through the cave, but the vines quickly regrew and spread new vines, rendering their effort futile.

”They just never die,” Kirk stiffened his lips when the vine grew again. He frowned at Spock. “Any idea to get rid of them?”

“My tricorder reading indicates that their weakness is acid,” Spock replied.

“Well, what’re you waiting for?” Kirk asked.

When the team sprayed homemade acids on the vines, the vines withered and shrunk, leaving open a space wide enough for them to cross through. With satisfaction, Kirk led the team inside the cave.

“Damn it,” Kirk cursed what he kicked off the spiders biting his legs.

There was a huge spider web inside the chamber, and Kirk soon encountered their creators. The spiders were small and fast. They were also numerous. With this rate of spider attack, Kirk and his team would soon be their dinner.

“Interesting,” Spock said, looking unaffected. Kirk was tempted to punch him. “The spiders are mechanical, and their movement pattern corresponds with the energy signature I detect.”

“You mean something here’s controlling them.”

“Most likely. If the device is located and disabled, the spiders will cease to function.”

“Work out where the energy signature comes from. Watch out for anything unusual,” Kirk ordered, looking around for anything that might control the spiders. As he waved a spider biting his arm away, he saw a glowing red light right under the web.

He shot.

The light went out. The spiders stopped. Kirk was relieved that it was over.

“March on,” Kirk said, moving on after he was sure that his words were followed. This trip had better work out, he thought, or I’ll set a fire to this damned cave.

In the next chamber, part of the wall collapsed, forming a stack of debris and blocked part of the pathway. “Are the roof and wall structurally sound?” Kirk asked Spock. No point risk being buried alive. “Anything interesting under the debris?”

“Yes, the structure is currently sound. I detect an energy signature from under the debris, but removal will threaten the structural integrity.” Spock said.

Kirk took a look at the debris. It was huge, and he really didn’t like the shape of the chamber it was in. “Go forward. After checking over the whole thing we can take a look of that.”

“Very well, Commander,” Spock replied dryly.

The path ahead narrowed down until they arrived at a dead end. There was a rising on the far left sturdy enough to support climbing and a spot of light above, so Kirk and his team used their equipment to start climbing.

The attack towards them began before Kirk even saw it coming.

When Kirk woke up with a headache, he found himself suspended above a spider web. He experimented with moving his arm and found that they were free. He must be really lucky to land on the non-sticky threads on the web. Under the dim light, he saw a giant black spider surveying the several adult-sized cocoons on the web. It must have ambushed the whole team when they were climbing up.

He would be next if he missed his steps and got stuck on it. If the spider worked like the Earth’s own, it would have detected him soon through the vibration of the web.He lied very still until the spider approached one of its prey and opened its mouth.

He shot.

The spider stumbled and the web shook violently, forcing Kirk to cling on the web with his free arm and legs.

He shot the spider repeatedly. It was hellish to aim at a moving target in dim light, but his life and the team’s depended on it. He also tried to remember which way the spider ran on to locate the safe parts of the web. Not an easy task either.

I wonder whether Spock’ll make a better job at that, he thought. Vulcan eidetic memory and all. Speaking of Spock, is he still alive or already eaten?

He wondered at his anger at the thought of Spock devoured by the spider. But then Spock was too useful to languish as spider food.

Finally, the spider collapsed and fell off the web. Kirk used a shoe to test the web when he approached his trapped team and freed them. One of the ensigns was a goner, but Spock was still in a whole piece among the others.

“Thank you, Commander,” Spock said, still looking unaffected despite the spider web pieces still stuck on him. It was a nice trick Kirk wanted to learn.

“You all need extra combat training,” Kirk said. “Let’s get out of here to see if there’s anything worth being here.”

Deep inside the cave, they found something that looked like a cross between a gingerbread man ornament and a machine gun, which later Spock analyzed it to be an electronic key to something, so the trip wasn’t a total waste. Kirk still took an extra shower to get rid of the stink.

---

 

It is worth it, Spock thought, when he examined another new discovery from their excursion to the underground cave system. Most objects they found were useless, broken or quirky - Spock was still mystified why anyone would make a trumpet that induce hallucination in its users that they were world class trumpet players and a compulsion to share their imaginary talents, which Ensign Crusher did not possess any. However, they also unearthed powerful weapons and objects that could potentially change the science that was known today.

Kirk gave him free reign of the lab after several excursions. “ I don’t need to know how you do it. I only need the result.” Sometimes he walked in to chat with Spock about his current work, and Spock enjoyed the interesting suggestion Kirk made about the objects’ potential use. It was ingenious though noisy to use the trumpet as a locating device on prisoners. “With the way they blow, even a blind guy can find them if they try to escape, and they won’t have much air left for that anyway,” Kirk suggested, and Spock found it creative.

“I wonder what machine the spider key is used for,” Kirk said over their another chess game, now a routine in their life. “I hope it’s something that earns us a bonus.”

“It may have been broken now,” Spock cautioned.

“Wet blanket,” Kirk accused, with no heat in his voice. “It’s still something to hope for. Anyway, checkmate.”

Spock was forced to concede and tipped over his king as Kirk patted his arm. “Let’s grab something to eat. Put it on my tab.”

“How can we put anything on your tab as we synthesize our meal from the common synthesizer?” Spock asked dryly.

Kirk only laughed. “I’m a man of surprise.”

Spock was surprised when Kirk inserted his card and took out a vegetable dish that Spock had never seen before. An admirable feat as Spock was certain that he had already exhausted the limited vegetarian options provided in the base. Spock raised an eyebrow.

It was a thick stew with a strong smell of chili, tomatoes, garlic and onions. He tasted it as Kirk pushed it to his side. It was very filling, with a lot of beans and potatoes. He poured another large spoonful of the stew to his mouth.

“It’s good. Isn’t it?” Kirk smirked. “You’re lucky that I happened to have some old food cards laying around. You can keep it for your own. Save my trouble of ordering it for you.”

“Thank you,” Spock said and meant every word.

“It’s no trouble,” Kirk said with a shrug and attacked his own dinner, a hearty chicken and beef dish.

---

 

“Nice to meet you, old pal,” The imperial agent smirked at Kirk, and smiled with revealed teeth. “Not expecting me, right, but I really miss our old school days together.”

“Cut the slack, Finnegan. What’re you doing here?”

“Routine inspection. You know the Empress’ standing order on special teams in isolated outposts.” Then he turned to Spock as if he were a piece of meat. “He’s the Vulcan you begged for as your sex slave, is he? Your taste is as bad as always.”

Your days are counted, Spock thought while remaining silent.

Kirk frowned and dragged Spock to him. “It’s not your business who I fuck. He’s mine and I also know people in the right place.”

“Possessive of your little pet?” Finnegan said. “I trust that even in your backwater outpost you can cough up a room for me.”

“Crusher, get these gentlemen settled,” Kirk ordered with a steel-like voice.

When Finnegan and his guards disappeared in their vision, Kirk released Spock and said, “I have some old business with this joker. Stay on your guard. I don’t trust him, but my hands are tied by the imperial order.”

“He claimed to know you from your school days.”

“Yeah. He was a senior and thought I was just another plebe for his hazing. He bit off too much for his trouble, but I should have known he would reappear again like a bad penny. Stay low until I know what tricks he has in mind.”

“Understood,” Spock said, planning for the worst.

---

 

Finnegan nitpicked every decision Kirk made and made the life here generally difficult. Spock could feel Kirk’s tension, but Kirk maintained an impassive face and failed to rise to Finnegan’s bait.

Spock stayed out of Finnegan’s way and remained out of his sight for several days. Then Finnegan went for him.

“You have an impressive record, Vulcan,” Finnegan said. “Why do you volunteer to come here? Want to be a cocksucker so much?”

Spock remained silent and focused on his work.

“It’s no way to address a senior officer,” Finnegan said with a growl. “Give me your agonizer.”

“With due respect, you cannot. As regulation 567.34 states, only a superior in the same chain of command is authorized for the use of agonizer, and you do not belong in that that.”

“How dare you-”

Finnegan’s words and punch were intercepted by Kirk, whose eyes were as cold as the snow on Delta IV. “I’ve told you Spock and the lab were off limit. Getting dementia in your age?”

“You can’t order me,” Finnegan jested. “And you’re right here to punish your subordinate for his big mouth.”

“Lieutenant Spock is a Vulcan. Think of it, Finnegan. The Empress will be displeased about any stalled progress because of your huge ego.”

“He plays you right in his hands. Never expect you to be a puppet of your Vulcan---”

Spock knelt by Kirk, pulled down his trousers and sucked him. With Spock’s mastery of human biology, Kirk came pretty fast. He licked Kirk clean, tucked him back and stood up again.

“Commander Kirk is my direct superior, and he has my total obedience and loyalty.”

Finnegan left dumbfounded.

Kirk’s face hardened when he said. “I can take care of myself.”

“I don’t do it for you. I do it for myself,” Spock replied, leaving without looking back. He needed to rinse his mouth to get rid of the taste.

---

 

It was awkward to face Spock after that. Kirk had few qualms in his life, but he never forced someone to have sex with him. Even though technically Finnegan forced their hands, he still felt guilty about Spock forced and humiliated before the bastard.

Spock was his people, and how could anyone respect a boss that got trampled on?

Finnegan was now cursing and limp after a convenient accident, but it was far less he deserved. Too bad Kirk lacked a good timing to get rid of him for once and forever.

As a person who faced problems head on, Kirk knocked the door to Spock's lab. It would be better to have their conversation in a neutral place.

Spock saluted him. “Commander.”

“Listen,” Kirk said, “I… am sorry about Finnegan. I don't like to make empty promises, but I meant it that you’d be off limit from his harassment.”

“Thank you, Commander,” Spock replied, as stoic as ever.

Kirk breathed deeply to suppress his temper. “What do you expect from me? If you thought it would make up for that, I could blow you right here.”

“It is not necessary,” Spock said. “As I have said I did it for myself, so no apology is necessary.”

Kirk softened his voice. “A game and dinner tonight? I miss our game.”

“I apologize that I will be unavailable tonight. Is tomorrow eight sharp acceptable?”

“Sure, I”ll prepare the board,” Kirk said while leaving.

Spock replied, “See you tomorrow, Kirk.”

A load of weight was lifted from Kirk’s chest.

---

 

Kirk knew Finnegan was up to no good when he showed Kirk the Imperial order to go to Cave 5312.834 with Finnegan as supposed observer, and insisted on only Kirk and Spock on the team, but the table could be turned from either side. Attempted to kill both Kirk and Spock, Finnegan was so idiotic that he triggered a cave slide trapping all three of them inside, and gloated about Kirk and Spock’s impending demise. With a well aimed phaser shot, Kirk got rid of him forever.

The fight and the cave slide left both Kirk and Spock wounded and bleeding. The main entrance was blocked, but with a spark of genius, Spock hacked into the machine in the room with the previous spider key and discovered its function as a transporter.

Through the haze of pain, Kirk looked around the cave to find a way out. He swallowed an expletive as his broken right leg hurt like hell. Whenever he twisted for a better look, his broken ribs made them known forcefully.

Spock’s face was dirty with blood, and his right arm twisted at an unnatural angle. However, he was alert and able to walk. Among the two of them, Spock stood a better chance to return to the surface alive and hanged on until reinforcement.

Kirk hardened his face. It was not in his nature to delay the inevitable.

“Spock, leave me here and get the hell away. You can come back for me later,” Kirk said, while knowing that it was unlikely Spock would do that. In the Empire, everyone looked out for themselves.

“It is unwise to leave you in danger,” Spock said with stiff lips, pressing around Kirk’s bleeding wound, and Kirk felt how tense Spock’s muscle was against him. .

“Listen. One of us must stay to operate the machine to keep the path open. No way I can crawl out with this leg, and I’ll only burden you if we leave together anyway,” Kirk said with a wince. “You’re a smart guy. I’m sure you can get your way out in one piece.”

“It was unbecoming to perform unnecessary self-sacrifice.”

“I’m not doing it for you, idiot. I’m doing it for myself. You heard what the asshole Finnegan said. Someone sent him after me and got us stuck here. Those bastards deserve what they have coming. I just want to ensure that they get their payback.”

“Kirk…”

“Go.” Kirk shushed Spock away, pushing the gear of the machine.

“Very well. I will come for you.” Spock tied the sling tighter and got into the position.

“You had better!” Kirk said, secretly relieved and frustrated as Spock was transported to safety.

For a long time, He was alone with the machine, only hearing his heightened heartbeat and the buzzing sounds it made, cursing his stupidity to end up trapped here alone. He hated that he still held a faint hope for Spock’s return, while he should have known better.

The chamber got cooler. Kirk finally collapsed.

---

 

When he opened his eyes again, his leg and ribs still hurt faintly, and the room smelled of disinfectant and cleaning detergent. The base nurse by his bedside bent down and said, “Keep still. I’ll call the doctor.”

Spock did come back for me, Kirk realized, feeling an unfamiliar sense of warmth radiating through his body.

The doctor pumped a lot of drug into him. When Spock visited him, Kirk was so drugged that he couldn’t even lift a finger.

“I trust that you feel better, Commander."

"What’s the status?”

“Everything is in order. Agent Finnegan’s subordinates are currently under arrest for sabotaging the rescue effort, leading to his undue death. One of them has already confessed, and within two days we should have concrete proof for the others’ involvement,” Spock replied in a dull tone, but his calculating eyes betrayed him.

“Clever,” Kirk said with a smile. Good coverup for Finnegan’s death, and a smart way to get information out of the underlings without tipping their enemies’ hands. “I’m sure you’ll do a thorough job. Report to me when it’s done.”

“Yes, Commander,” Spock said. Then his eyes turned to Jim’s leg held in a swing. “Welcome back, Kirk.”

“Thanks,” Kirk added with hesitation. “For saving me.”

“You are welcome,” Spock replied with eyes softer than usual. “Please understand that I I do not do it for you, but for the Empire It’ll be a great loss if an outstanding officer died in an accident.”

Kirk laughed, seeing through Spock’s unspoken words. “I’m glad that the Empire still have two of its brightest intact. Have you found anything about the machine?”

“I will report to you when I finish the examination. I expect it to be done within 47.5 hours”

“All right, chess later? I’ll be stir crazy stuck here.”

“I’ll bring the chessboard after my shift.”

As Spock left, Kirk watched his back and realized he found someone he came close to call a friend. He was unsure how he should feel about it, and how long this state of affair could continue, but risk was always his business. He stared at the ceiling, already planning his chess strategy.