Disclaimer: I don't own Star Trek, just my wonderful child and OC, Cassie.

"Shore leave is only 72 hours away."

There was a curse, and then the muttering continued down the wide pipeline that the Beta shift engineers occupied.

"72 hours, I can keep a level head for that long," a clatter, and then, "...Jesus fucking Christ."

"Language, Lassie!" Scotty shouted, and the woman in question turned around and glared at him, her hands on her hips, a wrench clutched in her fist.

"Fuck you, Scotty," she shot back, "this is the worst thing I've done on this ship. Ever. Who the fuck wired this thing?" She banged the wrench on the paneling, which echoed down the pipeline. Some of the other engineers chuckled, and Scotty rolled his eyes, turning back to his PADD.

Cassie continued working, occasionally muttering under her breath, the other engineers chattering in the background, Scotty and Keenser monitoring everything.

They were around two years into their five-year mission, excluding the long intermission where the Enterprise had to be completely reconstructed, and it had been six months since their last leave.

Cassie wasn't even the worst of them all with her stir-craziness; Scotty was just as bad, rumour said he'd met his soulmate on their last leave and wasn't doing so great with separation. Sulu was the same way, missing both the soulmate he was married to and their daughter. The worst of them all was, apparently, the Captain.

She had never met Jim Kirk, as she was constantly in the depths of the wires of the ship as chief of electrical and the warp specialist, but gossip traveled far, and the Captain was reportedly extremely stir crazy. Cassie was glad for it; this was a special leave, scheduled early, entirely because of the Captain.

As she worked, she could only speculate what made the Captain so restless. They hadn't had any massive incidents for a few months, aside from the occasional alien virus, memory loss, colony of children… well, no, they always had incidents. She had never seen any directly, she never beamed down to the surface, and was indeed pretty scared to even try it after Nero, Khan, and, most recently, Krall. The engineering department always lost the most people, and she was reluctant to be one of them.

Maybe the Captain had the feeling that he was going to meet his soulmate soon, perhaps the mark was getting darker. Hers was, which was why she was unusually interested in getting to Yorktown. And worried.

She put down the wire clippers she was using and wiped her forehead, pulling back her sleeve and looking at the chicken scratch script that circled her wrist. It had been getting darker and darker every passing day, slowly becoming legible, and after the scare she had during the Khan incident, she was grateful for it. Even though it had been a few years since the mark had faded completely and then suddenly returned, she was still terrified she or her soulmate would die. She was certain they worked in Starfleet, and possibly on the Enterprise, so there was no guarantee for their safety.

Cassie grimaced to herself. She wasn't even sure she wanted to meet them, whoever they were. No matter how happy other soulmates seemed, she didn't know how she felt about being predestined to be with someone. It was as though she didn't have a choice.

Scotty shouted something unintelligible, marking the end of Gamma shift, and Cassie wrapped up her tools, closed up the panel, and climbed back up into the main sector of Engineering with the others.

"Good work today, all of ye," Scotty was saying, nodding to each of them. "It's unlikely we'll be having any troubles, so I won't have ye come down here unless I explicitly call ye. That clear?" Everyone nodded, with a few tired affirmations here and there. Cassie just yawned, looking forward to getting into her quarters. "All right. Dismissed, and get some sleep, ye wee geniuses!"

Cassie allowed herself a little grin, saluting to Scotty on the way out, beginning the long trek back to her quarters in the officers' hall that was annoyingly close to the bridge. None of the engineers made small talk, all of them too exhausted to bother. Instead they kept trading yawns, especially once they were all confined to a turbolift. Cassie had the worst of it, yawning so wide that tears started to form. The lift stopped at various points, engineers stepping out of it one by one with halfhearted "goodnights".

Soon, Cassie was the last one left, and she leaned heavily against the wall, struggling to keep her eyes open. She'd worked too many shifts, apparently. Just as she was about to fall asleep on the wall, the turbolift opened, and she stepped out, right next to the bridge.

For a minute, she considered going in and checking on their progress. Then her soulmark started to ache slightly, so she grumbled and moved in the direction of her quarters. Nyota attempted to grab her attention as she passed her, but she merely grunted in response and pointed toward her door, and her friend grinned and let her go.

"Finally," she mumbled, opening her door. Her bed looked like a beacon of tranquility, and she collapsed into it.

Four Years Ago

"Lieutenant Andromeda, this is Commander Spock."

Cassie shook hands with the Commander, noting his slightly pointed ears and very Vulcan haircut.

"Nice to meet you, Sir," she greeted, and Spock nodded, releasing her hand.

"Likewise, Lieutenant. Admiral Pike tells me you're an exceptional engineer, and half Vulcan, like myself."

It wasn't a question, but Cassie took it as such.

"Yes, Sir, I am an engineer, however I grew up on Earth, not Vulcan. My mother was Vulcan, but passed away shortly after my birth, so my father elected to return here to raise me as if I was human," she explained, already aware of the infamous qualities of the commander and just how different they were.

"A logical choice on his part, it would have been difficult for a human to raise a half Vulcan child on our planet."

"Yes, Sir," she glanced at Pike, who smiled.

"Cassie will be joining the rest of the crew on the Enterprise, I thought it might be nice to know that the two of you share a heritage."

Spock smiled; it was tiny, but genuine, and he nodded to the admiral.

"It is nice to know, Admiral, that I am not the only half-Vulcan in Starfleet," he turned to Cassie, with some interest now. "Perhaps you and I have more in common."

Cassie grinned.

"Somehow I doubt that, Commander Spock, but I'm willing to get to know you. I wouldn't mind learning more about where my mother came from."

Present

Cassie grimaced, stretching her neck slightly, still waking up from her nightmare. It was the same one every night, starting with Vulcan disintegrating before her eyes, then the horrible pain as her mark faded from her wrist, the Enterprise crashing, being held captive-she shook her head of it, and got out of bed.

The dreams didn't really bother her anymore; that was the plus side of the Vulcan half of her. With Spock's help, she'd learned how to control her volatile emotions in a healthier way, the way Vulcans had evolved to do.

Her wrist caught her eye, and she rubbed her mark curiously.

She could read the writing.

Good to meet you, and if Scotty says you're the best, you're the best.

Well. She snorted. That was anticlimactic.

Soulmarks were always introductions, but most people were lucky enough to actually get someone's name in theirs. She guessed her soulmate wasn't all that polite. Neither was she, so she could live with it.

She took a brief round in the 'fresher, then dressed, taking care to cover her wrist with her sleeve, especially now that it was legible. She was actually looking forward to having a leisurely breakfast when her communicator beeped.

A sigh, then, "Lieutenant Andromeda here."

"Lass! Good, you're up. You're needed on the bridge, we've got a task for you, you get to beam down!" Scotty sounded enthusiastic, and she looked at the communicator in surprise. Scotty was usually the one to beam down when there was an engineering issue, but she didn't question it.

"I'll be right there."

On her way, Cassie speculated.

The planet they were orbiting wass a Class M inhabited planet that Starfleet had established a station on years ago. Recently, the station had gone offline, which was why they were there. The only reason she could figure that she would be needed was if the malfunction was something electrical.

When she arrived, everyone on the bridge was already discussing the situation.

Cassie caught Uhura's eye, and gave her a tiny wave, which she returned brightly. She moved over to where Scotty stood, and listened in on the explanation.

"The station isn't just for gathering data, it controls a magnetic field that protects the planet against the asteroids that keep blasting into it and keeps the electrical storms on the planet from getting too wild," Scotty explained.

"Doesn't that violate the Prime Directive?" Cassie piped up, and Scotty shrugged.

"Maybe, but Starfleet established it anyway."

"The planet is full of intelligent life," Spock explained. "At the time the base was established, the Prime Directive was not fully established." Cassie nodded, and Spock nodded back in greeting.

"So what about this electrical storm that's coming in?" Captain Kirk suddenly turned in his chair, joining in on the conversation. Cassie tried not to think about the fact that this was her first time meeting him.

"We've got three hours until it hits, Captain," Sulu chimed in, tapping away at his screens with Chekov.

"All right, Lassie, this is where ye come in," Scotty said, abruptly clapping her shoulder. Cassie raised an eyebrow at him.

"How, exactly?"

"Well, you're the best engineer I've got, and you're damn good at electromagnetics, so you're the best option to head down there and fix everything."

"Sir, I'm good at electromagnetics, but I dunno if-"

Scotty cut her off by leading her to the captain, and she grimaced.

"Jim, this is Lieutenant Cassie Andromeda, she'll be beaming down with you."

Kirk looked up at her, grinned, and held out his hand, which she took automatically. His eyes were way too blue, his blond hair swept back in a style that was remarkably appealing to her. His grin showed gleaming white teeth, and his eyes crinkled at the corners; it was a genuine smile, and she found herself returning it easily.

"Good to meet you, and if Scotty says you're the best, you're the best."

A tingle went up her arm, and she stilled imperceptibly, the smile freezing on her face.

Well, fuck.

"Yes, Sir, I'll do my damn best," she replied, on autopilot while her brain shorted out and curses repeated over and over in her head.

When they beamed down, she was still cursing to herself.

She'd never even spoken to the captain before today, and yet it was instinct to push him out of the trajectory of the incoming projectile.

Not a single thought was involved. She'd seen the creature aim for Captain Kirk's heart, and reacted. There was no logic, just action.

And then there was pain.

Pure and simple agony ripped through her as she was struck in her side, right beneath her ribs, dangerously close to where her heart may have been had she inherited Vulcan physiology. She'd shoved Kirk to the side, and in her haze of pain she remembered to look for him.

He was on the ground, unharmed but bewildered. For a split second, he looked up at her in shock, as she was beginning to feel it in her nerves as vertigo and nausea started to set in between waves of pain. She swayed, raised her blaster-but Spock beat her to it. The creature was dead before anyone else could make a move.

Blood rushed in her ears, she vaguely recognized that her pulse was all too fast, and her vision started winking in and out-the scene changed, and she stared at the sky.

McCoy's voice was muffled at first, but she fought through a fog that made her wish for sleep, and struggled to hear him and the commotion around them.

"Lieutenant, I need to remove this to clean the wound and make sure you're not poisoned. Can you hear me?" the Doctor said, his normally calm voice shaky. She felt a rush of guilt for worrying her friend. "Kid, can you hear me?"

Cassie nodded-she tried, at least, but everything was heavy and hard to move. She swallowed, and cleared her throat, absently grateful that she wasn't tasting blood.

"Yeah, yeah-" she croaked, painfully, "uh, okay," she swallowed again. There was no feeling in her left side; she assumed McCoy had already numbed it for her. There was a pause before anyone spoke again. The clouds had gotten darker above her.

"All right, it's out, but you've lost a lot of blood. I need you to stay awake, Cass, all right?" McCoy sounded better now, and she nodded slightly. She would try.

A moment passed, and somehow they had moved. Instead of looking up at blue sky, she stared at stalactites hanging from a rocky ceiling. Something in her shifted, and she was oddly fearful. She had lost time; had she passed out? Hit her head? Was she dying?

Her heart was beating fast, she realized, almost painfully hard against her rib cage. She tried to ask for McCoy, but her throat had closed up and she breathed hard through her nose. Her hands shook, and she felt suddenly cold. She closed her eyes, tried to remind herself that she was in shock, but she couldn't stop.

But then everything did.

Someone had placed a hand on her face, fingers at three specific points, and she recognized them in her head. A wave of calm washed over her; her pulse slowed, no longer thumping in her ears. It was Spock, and she sagged in relief. He would know what to do.

The coldness she had felt persisted, creeping through her veins from the starting point in her side. McCoy had not numbed her, she realized, she'd been poisoned.

As the thought ran through her mind, Spock withdrew both metaphysically and physically from her. Terrified, she tried to reach out for him, but did so only in her head. He was gone. She was in control again, but she felt trapped. She opened her eyes; her vision swam and she was nauseous again.

Blue eyes appeared suddenly above her as she refocused, concerned and stressed. She again felt guilty; they needn't worry, she'd be fine. She could feel it.

She wondered who that was.

The chill in her side was disappearing, and sound was becoming clear again. She closed her eyes-and with it came extreme and sudden searing agony.

She couldn't help the scream that ripped from her throat, but slapped her own hand over her mouth as she writhed in pain. The Vulcan part of her insisted that she needed to make sure no other creatures found them, but her human side reacted the only way it knew how to react to pain. She was crying, twisting her head back and forth, trying to find some way to get away from whatever hurt so much.

The pain did not die down, but somehow she managed to force it to the back of her mind, desperately clinging to consciousness and trying to find something else to focus on.

Someone was holding her hand.

"-I'm sorry, I'm so sorry, you're gonna be okay, god I'm so sorry, I'm sorry-"

She blinked her eyes open and looked around as much as possible without turning her head. They hadn't moved from the cave, and she was briefly concerned, and then someone squeezed her hand. The pain was an afterthought as she tried to see who it was.

It was the captain.

And he was holding the hand attached to the wrist with her soulmark. Slightly panicked, she checked to see it was still covered, and sagged in relief.

She shifted her head slightly, realizing that she rested on a soft pillow that was actually him. Bewildered, she blinked at him.

"Captain?" she asked, hoarsely, and he looked down at her in surprise and relief. "How long has it been?"

It was his turn to blink at her-he turned and shouted for McCoy, looking back at her with an exhausted smile. "It's been about ten hours, Lieutenant. We've been taking turns watching you, but I'll admit I took more than my fair share." He winked at her, but it went right over her head as her side ached again. He must have noticed her grimace, because he called for "Bones" more urgently.

Doctor McCoy appeared on her left, and shot her a gentle smile. "How're you feeling, darlin'? In too much pain?"

Cassie tried to shrug, "It's not the worst I've had, none of this is," she mumbled, and attempted to sit up, but both men held her down. "I'm okay, I can sit against something-"

"Sweetheart, not that I don't appreciate your tenacity, but you've just had a lung pierced and poisoned and scared the hell out of all of us," McCoy explained, lightly patting her shoulder but admonishing her protests. "Well," he frowned, and looked back at where she assumed Spock was standing, "most of us were scared."

"I'm half Vulcan, I heal somewhat faster, honestly," Cassie tried, a little impatient. "I don't want to take up any more time."

"Captain, Doctor," Commander Spock had reentered the cave, and gave her an assessing glance. "Lieutenant Andromeda is being entirely truthful, and at this point she should be stable enough for travel."

"Spock, this woman almost died-" the Captain began, but Spock cut him off.

"Your concern is well-founded, Captain, but if the Lieutenant is to get the proper amount of care it is imperative that we move to a location for transport before the electrical storm comes in." He paused, and nodded to Cassie. "If you feel well enough to stand, it is logical that we retreat to the ship and return to the planet tomorrow."

For a moment, Cassie was struck by how incredibly different they were despite sharing a heritage. Perhaps he was more Vulcan than she? She swallowed, and nodded.

"I'm okay to stand and walk," she confirmed, sitting up and not meeting any resistance other than a piercing pain in her side.

Before they could go anywhere, her communicator chirped, and Scotty's frantic voice rang through the cave. She fumbled at her belt and flipped it open.

"Scotty?"

"Lass! You alright?"

"I'm gonna be fine, what's going on?"

"Well, on top of the electrical storm, the planet's about to be hit with a, er, meteor shower. Literally."

Cassie made eye contact with the Captain, who had been staring at the communicator as if he was angry Scotty had contacted her instead of him.

"You've got to be fucking with me," she blurted, glaring at the device.

"'Fraid not. Either ye brave the storm and fix the field, or I beam ye back up right now. I've got it all readied."

Cassie closed her eyes.

It wasn't her call to make.

There was a moment of silence.

"Captain, my Lieutenant is the only one down there with the capability to fix the field."

Another pause.

"How long until the meteor shower?" Kirk asked.

"One hour," Scotty chirped.

Cassie looked at the captain, and tried desperately to keep her face blank. But she had grown up around humans, not Vulcans, so her despair surely showed on her face. The captain looked away, and she clutched her communicator with a tighter grip, already knowing his decision. Four valuable members of the crew, or a planet that was destined for destruction? The choice would be clear to him.

"Beam us up, Scotty."

The crew, always.

Her jaw clenched tight as she waited for the telltale tingling in her fingertips and toes. She knew, logically, that the choice was not easy for the Captain, but she wondered if the guilt would eat at him as it was starting to eat at her. She had saved his life, nearly at the cost of her own, and certainly at the cost of the life on the planet. Her injury was why they were returning-they would be caught in the storm with her, but needed her to do the repairs.

Her toes tingled, but nothing else did. Then, McCoy and Spock were both enveloped in golden light and disappeared, but she and Kirk remained. She looked at her communicator in confusion.

"Scotty?" she called, but only static responded. Light flashed outside-the storm had come early.

"Shit," Kirk swore, but Cassie saw an opportunity. Adrenaline flooded her bloodstream, and the pain disappeared.

"Captain, we have a chance," she closed her communicator and strapped it to her belt, glancing up at him when she finished. "There's a good chance we can get through this storm fast enough to the station before the meteors start coming in."

Kirk stared at her for a moment, but something must have shown on her face, because after a moment he nodded, his expression stony.

"Let's go."

Cassie nodded and led the way out of the cave, immediately pushing her pain to the back of her mind. Before the Captain could exit the mouth of the cave, she took his hand. She told herself it was for safety, not because of what she had discovered the other day. Then she shoved that thought to the back of her mind; that wasn't important.

"So we don't get separated," she explained when he frowned at her. He accepted it without even a tiny flirtatious remark. That immediately had her worried, given his reputation, but she pushed that away as well and began the walk to where she knew the station was. Not for the first time, she was grateful for her eidetic memory that came with her Vulcan side.

They didn't talk-normally she would have found this awkward, but she was too busy trying to watch her feet as they climbed up and down hills in the rain.

Occasionally she spotted evidence of more creatures and feared another attack, but nothing shot at them. She stumbled a few times, her side flaring in pain, but Kirk kept her upright and they continued on their way.

By the time they reached the station, the storm had gotten much worse, and Cassi was forced to regulate her breathing so she didn't stretch her fragile lung too much.

Kirk opened the door to the underground station, and the source of the malfunctions was immediately clear.

Everything, everything in the building was trashed. Someone, or something, had found their way in and torn the place apart.

Cassie felt her breath leave her in a rush, and swayed on the spot, horrified. For a moment, icy cold panic gripped her entirely. Her vision was fuzzy, and despair held her heart like a vise.

And then the Captain squeezed her hand.

The panic was shoved away, buried deep down by a part of her mind that she rarely accessed. A cool calm took over, and she recognized that her Vulcan half, her left brain, had taken over. She was thankful.

Her face was wiped clean of emotion, which is what may have signaled Kirk that it was time to let her do her thing. She looked around the room, determined.

"How much time is left?" She asked, sparing Kirk a glance.

"Thirty minutes," he replied, after glancing at his wrist. Cassie nodded.

"I can do this," she whispered, entirely to herself. Her hands went to her toolbelt and she was off.

Structurally, the place was ruined. But the structure, the aesthetic, didn't matter. What mattered was the wiring; the entire force field was based on electromagnetics. Cassie smiled wryly-Scotty had guessed correctly about the issue.

After getting over the initial shock of seeing the place trashed, the job was a simple one-for her, anyway. She salvaged what was still left of the electrical system, rerouted several main grids, rebuilt the control panel-none of it done to exact completion, she didn't have that kind of time. After she finished, a full team would beam down and complete her work.

Kirk called out a five-minute warning just as she finished wiring the control panel, and she had a tiny flare of panic, quickly squashed.

Calm again, she went through the motions of activating the shield.

Immediately, Scotty contacted the Captain.

"Captain! The Lieutenant's got the field online, no danger of meteors, and the storm is clearing up!"

Cassie smiled and let go of the lever on the control panel. Her side was aching again, but she ignored it.

"Give me just a moment and I'll beam the pair of ye up."

"Thank you, Mr. Scott," Kirk replied, and Cassie turned back to him. "Have Dr. McCoy ready to bring Lieutenant Andromeda to the Med Bay."

"Yes, Captain."

Cassie was suddenly exhausted. Something trickled down her side-her wound had reopened. She swayed slightly on her feet, and Kirk was immediately beside her, holding her arm.

"Hey, still with me?" He was concerned, and tender, so she nodded. It made him smile, and she realized, sluggishly, that she adored how it made his eyes crinkle at their corners. "Fantastic work, Lieutenant."

She grinned right back at him, her eyes bright despite her fatigue.

"Call me Cassie, Captain."

And then she blacked out, unaware that those were the words that had become legible in loopy handwriting on Kirk's collarbone that morning.

A/N: Oh boysie first Star Trek fic. Or first published one, anyway. Hey guess who super enjoys soulmate tropes? Me. Obviously. This is a fic that is gonna be pretty lacking in overarching plot because I am All About that good fluff. There'll be episodic plots, but aside from that, nah. Probably. An idea could strike me. I'll let you know. Not much else to say here. Are these notes really necessary? Maybe.

Anyway, please review! Love getting that good feedback.