Hello there, readers! This is my first Mass Effect story; it's a bit of a character study for my FemShep, and I hope it goes well, and that I don't make any mistakes... It's set during ME1, focusing around the Missing Marines assignment.

One small note -I headcanon that the entire squad deploys in the Mako for the planet missions in ME1, even though we're only allowed two teammates in the game. Apparently eight people can fit inside it, with a driver and co-driver - so for this story, imagine that Kaidan is acting as Shepard's co-driver, with the rest in the back.

I hope you enjoy!

WEAKNESS

Chapter One

Up until that moment, the last word Kaidan would ever have associated with Commander Shepard was weakness.

Strength always seemed to be a part of her, something as constant and definite as the colour of her eyes. It was there on Eden Prime, when she accepted Jenkins's death with grief, but practicality, and went on to take all the twists and turns of that mission in her stride. The geth, Ashley, Saren, the beacon - nothing could shake her. That same strength was there on the Citadel, where she listened to the Council with her face impassive, accepted their decision with nothing more than a slight tilt of her head that seemed to say, 'I expected as much,' and set out to track Saren down without showing the slightest sliver of worry about what might happen to her, to Earth, to humanity, if they failed. It was there on Therum, when she somehow managed to take out a geth armature with a malfunctioning pistol, faced down the krogan battlemaster with her arms folded and her voice steady, and led every one of them safely out of the ruins even as they collapsed around her.

With everything she did, she earned a little more of his respect. He knew that went for all of them, even Wrex, who barely spoke a purely friendly word to anyone. Yet right up until that moment, Kaidan respected her only as a soldier. He respected her as Commander Shepard, not as Helen Shepard.

Maybe he was drawn to her. It would have been hard for him not to be. After she pulled him out of the grip of the beacon on Eden Prime, and held nothing against him for what happened to her because of it… and that strength. Maybe, maybe, he was drawn to her, but never did he think of anything beyond that. One could very easily be fascinated by someone without getting any thoughts of breaking the fraternisation regs. It would pass, Kaidan told himself. These things did pass, when nothing became of them. And nothing would become of this, because even if he was drawn, he could never quite see her as a person. She was simply his commander. He knew she was a person, everyone was a person, but he found it hard to see her as one.

Until that moment.

He had never expected to see any chinks punched through that strength that gave her an extra layer of protection, over her shields and her armour. And it came as something of a shock to him when the moment happened.

It wasn't surprising that he was unprepared for it. After all, it was the last moment any of them had been expecting something of the kind to happen – the journey across Edolus had been uneventful. It had been perhaps ten minutes in the Mako from the drop point to the site where the distress beacon was beaming out its signal. The terrain was simple to navigate, which meant that they didn't even have to cope with the usual stomach-lurching drops and leaps the Mako normally made – whether they happened because of the Mako's notoriously difficult handling ('like a berserk, pregnant buffalo with cataracts,' was how Ashley described it, and Kaidan was inclined to agree) or that Shepard's driving skills left much to be desired, Kaidan wasn't sure, but it was a relief not to go through the normal shaking-up of his insides. The only thing of note that happened as the Mako made its slightly jolty way across Edolus's surface was that a handful of meteors javelined into a ridge a few hundred metres away, sending up a broad plume of grey cloud that half-obscured the horizon in that direction, along with a boom like a thunderclap. Tali let out a yelp and lurched sideways in her seat, away from the sound, and Wrex shoved her back with a low growl and a mutter of, 'What's your problem with explosions?' Kaidan thought he saw Shepard roll her eyes, but when he looked her way, her face was still as ever.

His memories of the rest of that journey were a blur. Just seconds among many. Information that when he finally slept, the night afterwards, his brain didn't consider worthy of retaining. After the meteor strike, his next memory of the journey was of his own voice saying, 'Almost there, Commander. We should see the beacon any moment now.'

From that short speech, everything else afterwards was always absolutely clear in Kaidan's mind. Every single second.

He remembered leaning forward in his seat to get a better look at the shapes coming into view ahead of them. The long dark smudge of the missing marines' transport, the paler cylinder of the beacon, and there, on the ground, the scattered heaps that he knew from the first glimpse were bodies. He bit his lip and glanced at Shepard. She looked back at him with the same grim resignation he felt inside him clear on her face.

'I was hoping they might be alive,' she said quietly.

'Nothing we could have done, Commander.' Kaidan shook his head. 'What do you think did it?'

She didn't respond except for a slight pursing of her lips which he took to mean, 'Let's go and find out.' She let the Mako roll a little way forwards, then drew it to a stop. The nearest body was perhaps fifty metres away. Kaidan squinted at it through the viewscreen. 'It looks like he's been… burned.'

'Not by fire.' A frown furrowed Shepard's brow. 'There's no charring. His body's just been eaten away. I wonder if –'

And then she snapped off the end of the sentence, something he'd never heard her do before. A stillness, a frozenness, very unlike her usual unruffled calm, settled over her body. She leaned back in her seat, away from the window. Her dark eyes were suddenly very wide.

'We have to get out of here,' she said, and the words seemed to scrape in her throat.

'What is it, Commander?' Ashley called from behind them.

'We have to go.' Shepard gunned the engine. 'We're getting out of here now.'

Garrus's voice rose over the thrum of the Mako's machinery. 'But what about Admiral Kahoku's men?'

'His men are beyond being helped. It's my men I'm worried about right now. Those burns are acid. And those patches of torn earth, there – you see them? The only thing that leaves marks like that behind it –'

The ground erupted.

As if it had sensed how Shepard's sentence had been going to end, as if it wanted to save her the effort of speaking it out loud, it came. Soil and rock exploded outwards as its head broke the surface, and the clack of stone echoed off the Mako's roof. Earth poured down its segmented form as it emerged. The head, then the body, then more of the body, and more. Claws twice as long as the Mako. A tongue-like protrusion from the mouth that glowed an eerie, unnatural blue. A screech that sent coldness sweeping right through Kaidan's body, pricking the hairs on his arms and making his insides clench into a knot.

Ashley let out a choked shout. 'Oh my God!'

'Thesher maw!' Garrus yelled, somewhat unnecessarily.

Wrex punched his fist into his palm. 'Ha! Yes!'

'By the Goddess!' Liara gasped.

All that came from Tali was another yelp.

'Holy – ' Kaidan began, then bit back the ending, remembering that he was still in the presence of his CO. And then he realised that Shepard, alone among them, had not uttered a sound.

He turned to look at her, and the moment came. The moment when he realised that she really was a person.

Because she was sitting staring at the monster rearing up out of the earth in front of them with sheer terror on her face. Her eyes were stretched so wide open that it looked painful. Her lips were slightly parted. And her expression was blank. Just blank. As if there was nothing in her mind but pure fear, fear that left no room for thought. Her hands were resting on the Mako's controls, and they were shaking. Almost imperceptibly, but shaking.

'Shepard!' Garrus roared her name over the thresher maw's wail. 'We have to move!'

Kaidan swallowed. I don't think she can.

Certainly, his commander showed no signs of even having heard Garrus speak. Her eyes were fixed dead ahead, on the worm-like monster now lining itself up with their tank - which suddenly seemed very small and very, very vulnerable.

Its head jerked, and a greenish liquid hurtled through the air and slammed right into them. Kaidan wasn't prepared for the force of the collision; the acid struck with enough force to rock the Mako backwards and to send himself and Shepard slamming against the backs of their seats - still, she didn't stir - and the others in the back falling into each other like armoured dominoes.

'That acid bypasses our shields!' Tali's voice was shrill with panic. 'Shepard, we have to get out of here!'

Ashley, Wrex, Garrus and Liara added their voices to the quarian's, but Kaidan stayed silent, because he knew it would be no use. He knew that the others couldn't see Shepard's face, since her back was to them, so they couldn't know that she couldn't move them, because as far as she was concerned, they weren't there to be moved. Their shouts couldn't reach her, because she wasn't there to hear them. In her mind, he could tell, she wasn't on Edolus. She was on Akuze.

He looked at his commander, still sitting utterly motionless, and wondered what he could do. Shouting obviously wasn't going to help at all.

'Commander?' he tried.

No response, and her eyes remained like that of a prey animal's. Maybe he should reach across, push her hands from the main controls, use them himself and get the squad to safety. Shepard clearly couldn't. It wasn't her fault, but she couldn't.

'What's wrong with you?' Wrex demanded. 'Playing dead doesn't work on threshers, Shepard! Put this thing into ramming speed!'

And suddenly Kaidan wanted to cover this up. To make sure they never knew that she had this weakness. He couldn't take the wheel, because then the others would know that something was wrong with her. The weight of responsibility hit him like a falling rock as he realised that the lives of everyone in this tank might now be in his hands.

He breathed in deeply. The thresher was pulling itself backwards, and even without knowing much about them, Kaidan could tell that it was readying itself to strike.

'Shepard.' Kaidan spoke a little louder this time, so she could hear him over the cacophony of the others' voices. 'You're not on Akuze. We need your help –'

The thresher lunged, its head knifing down towards them. Ashley swore, Tali cried out, Wrex bellowed, 'Shepard!' and Kaidan, on pure instinct, flashed out a hand and grasped his commander's arm.

And as if his touch had sent an electric shock running through her, she exploded into movement, her hand slamming forwards and her fingers punching down on the cannon control. The Mako jerked and spat out the blast. From the viewscreen, Kaidan saw the orange burst of light sear through the air, hitting the thresher in the mouth and punching right through. One moment, the creature was powering towards them at the speed of a bullet. And then the next, its strike lost its momentum, lost its direction, lost everything, and the thresher was flopping limply onto the earth, a smoking hole burned through its head.

Silence fell inside the Mako. Shepard leaned forwards over the controls, her eyes tight shut. Her shoulders were shaking.

'Oh, Keelah,' Tali said finally, her voice almost an odd intrusion into the quiet. 'Keelah…'

'The mouth is a weak point,' Wrex grunted, as if conceding a point. 'Good enough strategy.'

Garrus let out a shaky breath. 'Yes, well, next time, I'd prefer for us to use a strategy that doesn't make me feel like a… what do humans call it? A sitting waterfowl?'

Shepard swallowed and straightened up. 'We're heading back,' she said simply.

'Wait.' Ashley sounded a little confused, and when Kaidan glanced over his shoulder, he saw that she was tilting her head quizzically. 'Aren't we going to take a look at the bodies?'

Shepard's jaw clenched, so Kaidan decided he'd better come to her rescue. 'It's pretty clear what happened to them. Someone put the distress beacon here to lure them into the thresher nest.'

'Exactly. Nothing more to look into.' Shepard spoke quickly, and Kaidan was given the distinct impression that she was grateful to him for throwing her a lifeline.

Ashley shrugged and nodded. Shepard spun the wheel, and the Mako, in its usual juddering movements, turned away from the thresher nest and towards the extraction zone. Kaidan felt a sudden, powerful urge to see the Normandy again, and soon. The cramped interior of the Mako was always stifling, but right now, more so than ever. The sudden flash of terror from his commander was such a huge thing that it seemed to fill the entire tank, even though it had passed.

He glanced at her, and she seemed to catch him looking, because she turned her head his way. And for the first time, he found that he could read her features perfectly, tell exactly what she was thinking. You saw me in weakness. Please don't tell the others.

And Kaidan nodded, and gave her a small smile. He hoped she could tell what he was thinking, too. I won't.

She gave a tiny dip of her head, turned back to the viewscreen, and the rest of the journey passed in silence.

By the time they were back on board the Normandy, anyone who hadn't seen that momentary breakdown would have been completely unable to tell that it had ever happened. Shepard thanked them, as she always did, for their good work, even though they'd done nothing other than just sit inside the Mako and shout at her. She dismissed them, and went off to set up a comm link to Admiral Kahoku, and her voice was steady and her face calm. But Kaidan knew that the encounter with the thresher maw was still at the forefront of her mind, and that underneath the normal practical soldier exterior, he'd seen someone who was in need of help.

He procrastinated for a while, checking the contents of his locker, even though he knew they were all perfectly in order, then gave his armour a polish, even though he knew it was clean. Then he started up the stairs to the top deck - no real reason for it, he just wanted to walk around the ship and get his thoughts in order - and reached the CIC.

That was when Pressly made the decision for him. The navigator waved him over and pressed a data file into his hands. 'Since you're here, can you take that to the Commander? Just something she needs to sign for the Edolus mission. I'd take it myself, but Joker's being difficult about my course plotting, so I have to double-check the charts.'

So Kaidan nodded, and, somewhat grateful to have an excuse, crossed the CIC and made his way back down the stairs and over to the door to Shepard's cabin. It occurred to him, as he made his way towards the door, that he'd never seen the inside of her cabin before, and that it was likely that no one else on the ship had, either. To be sure, some of them might have seen inside back when Anderson was running the Normandy, but it was his cabin then, and now it belonged to Shepard. Whenever she was in there, the door was firmly locked, and even if she left it unlocked on leaving it, no one would ever have dreamed of going inside without her knowledge. For a start, you didn't do that to your commanding officer. And then there was the fact that it was this commanding officer.

It wasn't just that everyone respected her too much, Kaidan mused. They all did, of course they did, but it was something else, too. Shepard was just so… private. She was happy to talk to people, but it was always so hard to tell what was thinking about. He'd never heard her discuss her feelings. She wasn't not cold, not by any means, nor was she distant. Most likely she just didn't feel comfortable talking about the deep stuff around her colleagues, and that was definitely something Kaidan could understand. After all, when it came to keeping oneself to oneself, he wasn't exactly inexperienced.

So he couldn't help but feel a little guilty as he approached the cabin, because he found himself… not eager, exactly, but interested, to see inside. He knew that most likely Shepard will have kept it neat, orderly. No clutter, everything in the right place. She was a soldier, after all. So there probably wouldn't be anything lying around that could give him a clue to who exactly she was. Sure, he knew her story. Navy brat. First human Spectre. And… Akuze survivor. But that - that was what she was, not who. And he wanted to know her. And she probably didn't want him to.

It wasn't nosiness, he told himself. Well, maybe a little. It was probably nosiness. But he was just interested. In, well, her.

And he wanted to help. He'd seen her face as the thresher maw reared up over them, and he needed to know that she was all right.

He lifted his hand and rapped at the door, glancing over his shoulder as he did so. It felt like disturbing the commander was something that just shouldn't be done, even though he was just bringing her a form about Edolus, even though Pressly had ordered him to bring her a form about Edolus, even though she was most likely expecting someone to bring her a form about Edolus. At any moment, Kaidan felt, someone was going to stop him and demand to know what the hell he thought he was doing.

But that didn't happen. What happened was that the door slid open, and Shepard, standing on the other side, gave him a small nod and glanced down at the datasheet he was holding. 'That something for me to sign? About Edolus?'

'So Pressly says.' Kaidan held it out to her, and she plucked it from his hands. As she flicked her eyes over it, he let his eyes travel past her; he couldn't help but be intrigued by the contents of her cabin, intrusive as he knew it was. What he saw surprised him; the walls weren't plain. She'd stuck something up on them. Quite a few somethings, actually. Pieces of paper, as far as he could see. It made him raise his eyebrows. Real paper was hard to come by these days, away from Earth, at least. It was just so much more practical now to do things digitally. And he wouldn't have expected her to be the kind to decorate her walls.

She must have noticed him looking, because she followed his gaze and said, 'I draw things, if you're wondering. Good way to pass the time when we're en route.'

Unsure of how to respond to this, Kaidan just nodded. She, of all people, was an artist? Again, the thought crossed his mind that this was the last thing he'd expected of her – or maybe it wasn't. He knew she was quiet, introspective. Her quietness clearly hid a brain that was constantly thinking. And since she never really voiced her emotions to anyone else, art might be a good way for her to express them. When he thought about it, it wasn't all that surprising.

As this train of thought came to an end, he noticed that she was looking at him expectantly, as if waiting for him to say something else. Of course – he'd delivered the form. She must be wondering why he was still standing in the doorway. Or maybe she was just waiting for a response to her last statement.

He'd had a few talks with her before, and he'd enjoyed them. Mostly he'd talked about his biotics training. It was refreshing, finding someone he trusted with that part of his past, though he didn't feel yet like telling her about what had happened with Rahna and Vyrnnus. That was the thing – she wasn't distant. She was stoic and reserved, but she was easy to talk to once you got her to talk, and she went out of her way to try to connect with the crew. She just didn't talk much about herself. That was why it was so easy to see her as nothing but a soldier. Even in the conversations they'd had before, Kaidan had seen her as a soldier. Now, he looked at her, and he found himself wondering more than ever before about her past, her thoughts on the world. So he stayed standing there, and kept the conversation going. 'How long have you been doing that? The art?'

'It's not art so much. It's just drawing.' Shepard raised and lowered her shoulders. 'I've been doing it ever since I was a kid. I was on my own a lot, with both parents out on duty. Started doing it to pass the time and just never stopped.'

'Must have been hard, not having them around.'

'It wasn't really, actually. I was used to it. I'd never lived a life where my parents were around the whole time, so it just seemed normal to have one or both of them not there.' She gestured to one of the nearest drawings; from what Kaidan could make out at a distance, it was a sketch of a frigate in flight. 'See that? That's my birthplace. The Lexington. I was born on board. And I grew up like that, on ships. So even when my parents weren't around, there were always crew there to keep an eye on me, stop me from getting into trouble.'

Kaidan raised his eyebrows. 'I can't imagine you causing trouble, ma'am.'

She gave a slight chuckle. 'You're right. I had military discipline drummed into me the moment I was old enough to toddle. Part of the reason I ended up here. Just never knew anything else.' As if anxious to reassure him, she added, 'Not that I'd ever want anything else.'

'You never even thought about having a different career?'

'Not for more than about ten seconds at a time.' Her face froze suddenly, and her gaze dropped to the ground. 'Actually, that's a lie. I considered it pretty strongly after Akuze.'

She turned around suddenly, striding towards the table in the centre of the cabin and dropping the Edolus report onto its surface. Kaidan glanced over his shoulder, wondering if he'd been nonverbally dismissed, but just walking away from a conversation was so unlike Shepard that he stayed long enough to see her turn around and gesture for him to follow her inside. With the sudden feeling that he was encroaching on forbidden ground, Kaidan did so.

Shepard indicated for him to take a seat next to her at the table. She sat for a while with her eyes directed on the tabletop, her hands clasped together in front of her. Kaidan knew she would speak when she was ready, so he watched and waited, and eventually, she breathed in deeply and looked at him. 'Alenko, I owe you an apology. I owe the entire squad an apology, but since I think you're the only one who actually noticed, I can only really give it to you. Guess I'm too much of a coward to tell the others about what happened.'

Kaidan swallowed. 'Commander, it's not…' He hesitated, searched for words, and tried again. 'You're not a coward. I think anyone could understand you being…'

He backed away from the final words. He did not, he realised want to hurt her by suggesting that she was weak or afraid.

'Scared to death of thresher maws? You can say it.' She gave a small, bitter shake of her head. 'That was the first one I've seen since Akuze, but I knew I still had the phobia. I can't even hear the name aloud without getting this… chill. Still, I never thought seeing one again would affect me so badly.'

'It was all right in the end, though. You killed the thresher. No one got hurt.'

She gave another head-shake. 'You don't get it. A thresher maw was coming right at us, and I froze up. I couldn't move. I could barely think. I'd forgotten that you and everyone else was there. I was right back on Akuze, and the only reason we survived is because I reacted just like I did then. The first thresher I fought, I killed by throwing a grenade down its throat as it came for me. In my head, I was fighting that same thresher. I didn't fire the Mako's cannon to save you and the others, I fired it to save myself.' Her hands balled into fists. 'What does that say about me?'

'Nothing.' The word was an instinctive reaction, but Kaidan knew as he said it that it was the truth. 'Commander, everyone in the squad knows that you'd do anything to keep us safe. What happened back then isn't something that'd happen normally. You weren't yourself.'

'Well, I should have been.' There was more bitterness behind the words than Kaidan had ever expected to hear from her. 'My job as your commander is to keep you alive. I've never worked with a team like this before. If I got you killed, like I got everyone killed on Akuze –'

'You didn't get them killed. Akuze wasn't your fault.'

There was a sudden silence, as Kaidan realised with a mixture of mild horror and utter surprise at himself that he'd just interrupted her. That was… really not like me.

He waited for a scolding to come his way, but it didn't. All Shepard did was to bow her head slightly.

'I made bad calls on Akuze,' she said softly. 'Once we'd lost our CO, and half of us had scattered, and people started looking to me to find us a way out… I was meant to do that. I was meant to find a way to save them, and I didn't.' She looked up sharply. 'Don't think I can't deal with it. I wouldn't be on the front lines if I couldn't deal with what happened there. I'm fine. Or I thought I was.'

The final sentence of this speech sounded so… so hollow, so disappointed, that Kaidan found himself wishing that she were anyone other than his CO. Someone whose shoulder he could place a comforting hand on. But she was his CO, she was Commander Shepard, and he couldn't do that, no matter how much he wanted to.

Instead, he did the next best thing he could think of, which was to meet her gaze and hold it. 'Commander, I… I won't… tell anyone about – what I, you know, what happened.' God, why couldn't it be easier to just find words? 'But if Williams and Wrex and the others knew, I don't think they'd hold it against you. You saved all our lives back there, even if you weren't really conscious of it. And anyone could understand why you'd hate thresher maws.'

Something that might have been a smile, or an attempt at one, pricked at the corner of her mouth. 'Thanks, but I don't want to risk it. Wrex would probably tell me to grow a quad, and the rest… I don't know. I guess I don't want to be judged.'

The openness of this last statement took Kaidan by surprise. He couldn't remember her ever having talked so freely about her feelings before. He swallowed, considered the statement he was thinking of making, and decided to go ahead and make it. 'I'm not judging you, ma'am.'

'I can tell. Thank you.' Shepard's expression grew thoughtful. 'If one person had to see me break down, I'm glad it was you.'

Kaidan had absolutely no idea how to reply to this. All he knew was that it made a warm feeling stir inside him.

'Did you ever read a full report on the Akuze incident?' Shepard said suddenly. 'I mean, with a list of names of the people involved. Details.'

Frowning, Kaidan shook his head. 'No.'

'No reason why you should.' Shepard sighed, placing her elbows on the table and resting her chin on her hands. 'So you don't know – '

She stopped in mid-sentence, closing her eyes and gritting her teeth, then rose to her feet and took a few steps towards the wall. Not a dismissal, Kaidan realised quickly. Just the frustrated pacing of a person trying to sort out their thoughts.

For some moments, she stood with his back to him. Then she turned back around, nodding slightly, as if she'd made an agreement with herself.

'I feel like I owe it to you to tell you why it was they affect me so badly.' She didn't meet his eyes this time. 'Thresher maws, I mean.'

Kaidan's brain instantly generated two responses to this statement, which his mouth foolishly attempted to say at the same time. 'You don't owe me – they ate your whole squad, right?'

Not the most coherent speech he'd ever made, but Shepard seemed to understand. 'Maybe not, but it might make me feel better. And yes, they did, but there's more to it than that. If you'd ever seen a full report of the mission, you'd know.'

She slipped back into her seat. 'Everybody knows that Helen Shepard made it off Akuze alive. And that's true, but they never seem to remember the name of the officer we were serving under. That squad wasn't under my command, not at first. I just took over once everyone above me had been killed. When we landed, before the attack started, our CO –'

Again, she stopped. Her hands clenched tight together, and Kaidan saw the brown skin over her knuckles pale to white.

'His name was Isaac Shepard.'

And so my longstanding tradition of giving my OCs tragic backstories continues... though in this case, I suppose Bioware came up with Sole Survivor Shepard's backstory. I just made it a little more personal for Helen, and you'll learn the details of how next chapter. This story will just be a two-parter, but the second chapter is already written and will be up soon.

Thanks so much for reading!