A/N: This was a fill for a prompt on the ME kink meme. The prompt was, as written by the OP:

"So... I want to see a story, in which Shepard was so pissed and hurt about what happened on Horizon, and she decided to have some payback. She cheated on Kaidan with Garrus. Some part of her brain was screaming that it's not right, and she's ruining her friendship, but at that point she did not care.

And Shepard thinks, that one day that bastard will understand and crawl back to beg her forgive him. And she will...

Time passes. She is not so angry any more. And Garrus is always close to her, always watching her six, always cares about her. But he's not an idiot and he knows that he is... replacement. And it didn't stop him, because, you know, he always had a crush on her.

And when she is in custody, it's Garrus she's thinking about, not Kaidan.

And when Shepard meets Kaidan again before the attack... It's nothing. No feelings. No pain. No regret - because... because she understands that there is someone out there, who she really cares about. And if Kaidan wouldn't walk from her, she would never knew.

Turns out, even revenge can bring something good..."

Big thanks to The Red Celt for beta reading and for her very helpful suggestions.

An important note to new readers: The story starts out somewhat slow, but it gets more fun later on. So I hope you'll keep reading even after the first, admittedly less interesting chapter. ;)

Disclaimer: BioWare owns Mass Effect and its characters. I do not make any money from the writing of this story.

It was bad enough to wake up on a cold and hard operating table in some unknown lab, wincing from pain as she listened to the disembodied voice of a woman barking instructions at her to fight through the station without knowing anything about where she was or how she got there. But to find out that she'd died and spent most of the last two years in that lab being rebuilt and brought back to life by Cerberus, as if she was a robot that just needed booting up to be used again and again while her friends had scattered all over the galaxy—it was almost too much. She tried not to think about the pain, both physical and emotional, that this whole situation left her with, but instead concentrate on the present and the undeniably important task of finding out why humans were abducted on distant colonies and by whom.

This plan worked during the day when she was busy finding allies to fill her team with, undertaking missions the Illusive Man sent her on and fighting mercs, mechs, gangs—whoever was in her way. But the nights were an altogether different matter. Lying in her bed, staring up at the ceiling, the memories of Kaidan—his smile, his touch, his kiss—flooded her mind and set shivers down her spine in hopeless waves of desire. She had no idea where he was and whether he even knew that she was alive. She didn't think so; it wasn't as though Cerberus had broadcasted the fact—at least, as far as she knew.

She'd bumped into Tali on her first mission when they'd gone to investigate a recent attack on Freedom's Progress. Shepard had been glad to see her young friend and hoped that she could convince her to join her team again, but Tali had other responsibilities now. So, once they'd talked to Veetor and found out as much as they could about the Collectors, Shepard was forced to return to the Normandy without her, and she felt even more alone than before. Her old squad had moved on with their lives and there was nothing she could do about it.

She was glad to at least have Joker and Dr. Chakwas aboard; it was nice to have familiar faces on the ship. But the darkness that had enveloped her new life only really started to lift once she found Garrus.

She felt as if a little piece of her heart was given back to her when Archangel, the mysterious vigilante they were looking for, took off his helmet and Garrus's face came into view.

"Shepard," he said, his exhaustion almost palpable in his voice, "I thought you were dead."

"Garrus!" She flashed him a happy smile and opened her arms wide as if she was about to give him the biggest hug of his life. If turians even hugged—she wasn't quite sure about that, so she lowered her arms back down and simply asked, "What are you doing here?"

"Just some target practice with these idiots." He nodded towards the bridge as he rested the butt of his rifle on the ground, holding onto the barrel as he sat down on the back of a couch with a sigh.

"Are you okay?"

"Been better, but I'm glad you're here."

And just like that, he simply accepted the fact that she was alive. No questions, no accusations—it was as if it had only been a couple of days since they'd last seen each other.

Fighting alongside him again was the most normal thing that had happened to her ever since she'd woken up in that lab. They'd always worked well together, and this time was no different. Having him by her side, joking and strategizing with him: it was just like old times.

Then that damned gunship came and nearly killed him. She knelt by his side, willing him to hold on despite the blood gurgling in his throat with every desperate breath he tried to take and the light in his eyes fading with every second. The thought of losing Garrus right after she'd just found him felt like her heart was being ripped out of her chest again. She ordered Jacob to radio Joker to get them out of there and have Dr. Chakwas prepare for their arrival.

Once they were back on the ship they rushed him to the medical bay and he spent hours in surgery, attended to by both Dr. Chakwas and Professor Solus. Shepard paced up and down the briefing room the whole time, waiting for some news about the outcome of the operation and hoping that, even if he was not going to be able to join her team to fight the Collectors, at least he was going to pull through and survive the rocket that had torn through the right side of his face.

When Jacob finally came in and said, "Commander. We've done everything we could for Garrus, but the damage was too extensive," her heart sank. She had to hold on to the edge of the table to control her shaking hands.

"Mordin and Dr. Chakwas repaired his injuries with surgery and some cybernetics," Jacob continued. "We think he'll have full functionality, but—"

He was interrupted by Garrus striding into the room. Shepard let out a relieved sigh and finally let go of the table as a smile spread across her face.

"Nobody would give me a mirror. How bad is it?" he asked, and at that moment she knew that everything was going to be all right. He was back, alive and—other than his face being scarred and bandaged— he was doing well, and she couldn't resist the temptation to tease him a little.

"Hell, Garrus, you were always ugly. Slap some face-paint on there and no one will even notice." she quipped with a smirk, folding her arms across her chest and leaning back on one leg.

"Hah... oh, don't make me laugh," he chuckled, then winced in pain. "My face is barely holding together as it is—though maybe that's a blessing in disguise. Some women find facial scars attractive. Of course, most of those women are krogan..."

Jacob shook his head, impressed by the indestructible turian, then saluted Shepard and left the room. As soon as he was gone, Garrus's voice turned serious.

"Actually, I'm more worried about you. Cerberus? Really? You remember all those terrible things they did?"

"Yeah, I know. But the Collectors have been abducting whole human colonies and nobody else cares. Cerberus has the will and the resources to try to stop it. So I'm working with them—but not for them," she explained. "That's one reason I'm glad you're here, Garrus," she added. "I need somebody I can trust at my side; somebody to watch my back as I walk into hell. Again."

"Just like old times." His mandibles flared in a cocky smile, but he soon continued in a more serious tone, "The docs would tell you otherwise, but don't believe them. I'm fit for duty whenever you need me. Until then, I'll see what I can do at the forward batteries."

He turned around and left, and for the first time since she'd woken up and found herself in this impossible situation, she felt like she was finally not alone. It was good to have him back. Just like old times.

Garrus had just finished entering some firing algorithms when the door opened and Shepard walked in. He'd been settling in, familiarizing himself with the ship and the weapons systems and pondering the events of the last couple of days. He'd been fighting off wave after wave of mercs at his hideout, and he wasn't sure how much longer he could have made it on his own. He was vastly outnumbered, and—though he'd managed to foil the mercs' various attempts at killing him, funneling them onto the bridge and picking them off one by one—he knew that there was no way out and he couldn't have held them off forever.

Then he spotted Shepard in his rifle's scope and everything changed. He recognized her right away; there was a distinct way in which she moved and directed her team, and once she got closer, he could see her face and he knew that it was really her. To say that he was shocked to see her would have been a tremendous understatement. After all, she had been declared dead two years before—he'd attended her memorial service, along with the surviving crew of the Normandy, solemn and heart-broken. But her body had never been found, so when she suddenly appeared at his base, fighting through those damn mercs and closing in on his position, he simply accepted the fact that the Spirits had finally decided to stop torturing him.

And now here he was, on her ship again, and even though he hated Cerberus, he was willing to work with them—as long as he could fight alongside her again.

"Shepard. Need me for something?" he asked, turning towards her.

"Have you got a minute?" She stopped at the railing and her gaze fell on his face, her expression full of concern as she examined the scars and the bandages.

"Sure. Just checking the weapons systems." He made a wide gesture towards the console behind him that he'd been working on for the last couple of hours. "I can't believe Cerberus rebuilt the Normandy—and they even added a few really nice upgrades. We should have teamed up with them sooner," he drawled, flaring his mandibles out in a toothy grin.

"How are you getting along with the crew?"

"Reasonably well. They are as friendly as Cerberus people can be towards a turian." He shrugged, then looked at her and hesitated a bit before he continued, "How did you end up with them?"

"I'm... not sure. The last thing I remember is abandoning the Normandy. I managed to get Joker's ass into an escape pod, but I couldn't quite make it. I got sucked out into space, and my suit was damaged. I... couldn't breathe." Her heart began to beat a little faster and her throat went dry as she recalled those terrible seconds when she was gasping for air while she desperately tried to stop the leak. She shivered, but managed to repress the slight panic that threatened to resurface at those memories, and went on. "The next thing I knew I woke up in a lab. Cerberus had managed to rebuild my body. Don't ask me how," she smirked. Those details were still not clear to her, but it didn't really matter; the end result was the same. She was alive, thrown back into the fight to save humanity—and the whole galaxy—once again.

"Damn. I'm sorry. I mean, I'm sorry about the dying part, uh, that is, the not being able to breathe thing, ah, you know," he coughed, trying to dig himself out of the hole he suddenly found himself in. "But... I'm really glad to have you back."

"Thanks, Garrus." She smiled at him and patted his arm. "I'm glad to have you here, too. Do you have any information about the rest of the crew?"

"Not really. After you, ah, died, we just drifted apart. Tali went back to the Fleet and, as far as I know, Wrex returned to Tuchanka. I'm not sure about the Alliance people."

"And what about you? How did you end up on Omega?"

"After the Normandy was destroyed I trained to become a Spectre, but it just didn't work out. Got tired of all the political bullshit and red tape on the Citadel. Omega, on the other hand..." His voice drifted off and he started to pace up and down as he recalled the outrage and disgust he'd felt when he'd first arrived at that hellhole and witnessed the atrocities the different gangs committed without any repercussions. "Omega was filled with criminals and nobody gave a damn," he ground out. "There had to be someone to stand up to the local thugs. Someone people could believe in."

Shepard nodded at that, then crossed her arms and leaned back against the railing as she watched him move around in the small space. "And how did you end up with a team?

"I wasn't the only one who wanted to do something about the situation. A lot of people had been affected by those thugs' activities. Some of them were willing to step up to the plate—especially when they saw that I could get things done." He stopped and stared off into the distance as the faces of his crew flashed up in his mind. "There were humans, turians, even a salarian and a batarian. They all lost somebody to the mercs, or did things themselves they wanted to atone for. I gave them hope. And now they're dead. Shows what I know." He shook his head as he stared at the floor.

"What happened?"

"There were twelve of us, including me. I thought they were all loyal; I thought we all wanted the same thing. Apparently, I was wrong. One of them betrayed me: Sidonis," he spat out his name as if it was poison and his eyes narrowed in rage. "He lured me away from the base and while I was gone, the mercs attacked. So now everyone except me is dead—all because of him. And because I didn't suspect anything."

"Are you sure he betrayed you? Maybe they killed him first."

"No. I did some investigating, checked with old contacts. He booked transport off Omega just before the attack, then withdrew all his credits from his private accounts before he left. He sold me and everybody else on the team out and ran. They were all good men, and now they're gone while he's somewhere out there, living off his blood money. But one day I'll find him... and fix that."

There was a menacing growl mixed with bitterness in his voice, and Shepard knew that eventually he'd make good on his promise. She wasn't sure if that was the right thing to do—revenge might be sweet in the heat of the moment, but sometimes it just made things worse in the end. It wasn't like him to kill someone in cold blood and she was afraid that the ramifications of doing something like that would be worse for him than the satisfaction he would get out of it, but she let it go for now; she decided that they'd cross that bridge when they came to it. So she just nodded her head again and hummed emphatically as she watched him turn back to his console.

"Thanks for coming by, Shepard. I have some work to do," he said, his voice still strained with anger, and she knew that her time was up. As much as she wanted to be there for him, he needed his space at that moment.

She turned around and left, her heart aching for him, determined to help him through this—no matter what it would take. After all, he was her friend . . . her only friend left in this universe.