This happens directly after Chapter 35 of Ante Up

Garrus found himself sitting alone in the mess some hours after Jack's surgery. It was late enough that the Grissom students had given up on trying to see their teacher and most of the crew had already retired to the bunks. For a while, Liara had provided Garrus some company, but even she had given in to sleep eventually. Shepard was currently in the Med Bay, submitting to a check-up from Chakwas, and she intended to have Jack moved up to her cabin once she was out of the critical zone so she wouldn't be bothered.

The sudden shriek of chair legs scraping the floor caught Garrus' attention, and he stared wide-eyed up at his father as the older turian sat in front of him. Garrus muttered, "Shouldn't you be asleep?"

Aetius scoffed, "I'm not the one who's been fighting all day."

Garrus said nothing, just folded him arms on the table and buried his head on top of them. His father knew something was wrong, but it wasn't something Garrus really wanted to talk about. He knew Aetius wasn't going to leave, though, so he lifted his head slowly.

"Do you remember," Garrus began quietly, "when I was a kid, I asked you why you never said anything about fighting in Relay 314?" He looked lazily over to his father. "I heard so many others talk about how intense the battle was, how they served with bravery and conquered the unknown. It seemed like something to brag about, so I never knew why you didn't."

Aetius nodded. "I told you there was nothing pleasant about that fight and that there was no glory to be found in it."

"And that is was painful to think about because Aunt Phaedra died there." Pallin's mate, who had been killed during the 314 Incident, before Garrus had even been born. Aunt was the closest word to describe her. Had she been alive, she would have helped raise Garrus and Solana. "You said that they hurt her very badly, but I didn't really know what you meant by it."

Aetius stayed quiet, so Garrus continued. "When I was older, I had the bright idea to ask Pallin what happened to her, but he never gave any specific details. Just said that the humans had done terrible things and that he returned the favor. I always wondered, just like a stupid kid, what would have made him so angry that he would murder a bunch of humans, that he would commit a war crime."

"You figured it out eventually, I'm sure," Aetius said, keeping eye contact with his son. It was a sort of interrogation, this conversation.

"I had ideas," Garrus said, "but they all seemed so impossible. I've fought. I've killed people. But even if someone hurt Shepard, I don't think I could just murder everyone in the near vicinity out of rage. Pallin killed people that had nothing to do with her death, just because the were too close."

"There's a reason we covered it up, Garrus," Aetius warned. "There's a reason we protected him even though he committed acts that our people consider inexcusable crimes."

"I know," Garrus said. "Seeing someone killed, shot, torn apart by Reapers... none of it has ever really bothered me. But, to see someone laid open like..." Garrus felt nausea flood his gut again, like it had when he first saw Jack on that cot.

"You were lucky to have found her in time," Aetius said simply, knowing exactly where the conversation was going.

"How do you live with it?" Garrus murmured.

"Knowing that we didn't get to Phaedra in time..." Aetius hissed, his eyes closing. "We don't live with it, and that's the problem. It's impossible to live with something like that." He glanced toward the Med Bay, where the window was still covered over. "And you wondered why I didn't want you to leave C-Sec. There are terrible things waiting for you on the outside, Garrus."

"If I had know that this is what I would find..." Garrus's mandibles clacked against his face. "Jack... she has all those tattoos, but underneath them she's got so many scars." He crooned as he admitted, "I never thought much about them. I was always more focused on the tattoos."

Aetius stood, showing very subtle signs of discomfort. "They served their purpose. They're laid out in a way that hides the scars."

"A lot of them," Garrus hummed offhandedly. "They almost make me uncomfortable. Dizzy." His father gave an affirmative trill. "You too? I noticed you don't really like being in the same room as her, even."

Aetius turned quietly. "No, but I wasn't ever looking at the tattoos." Garrus' maw clipped shut as that sick feeling hit him again. "Good night, son."

"Yeah," he replied as his father stalked away. "Good night."

We don't live with it, and that's the problem. Jack was a walking reminder. Her entire body was covered in flashy tattoos meant to draw attention, but all his father had ever seen were the remnants of dissection. Garrus had never thought of his father as anything but.. .strong. Immovable and untouchable. But, he was just like everyone else. Haunted by the past and a life that he hadn't saved.

When Shepard slipped out of the Med Bay, it scared Garrus far more than he'd care to admit. "Hey, we're ready to move Jack upstairs. Give me a hand?"

He barely turned. "How is she?"

"Sleeping," Shepard said. "Her vitals are stable and Chakwas says she'll come to in the next hour or so."

When he was slow to respond, Shepard moved up to him, laying her good hand on his arm. He stared at it, could see cracks of cybernetics glowing red on her inner arm, as he usually could when her body was trying to keep up with her. Uneasy, he covered the light with his hand.

Cerberus had done that, too, made Shepard-his Shepard-their lab rat for two years. Even now, she held the traces of their experiments hidden under her skin. His thoughts raced in panic as he thought of Jack again, thought of the doctor's voice as he laughed at her pain. Sure, Miranda had headed the Lazarus project, but she hadn't monitored Shepard around the clock. What had those doctors done to his mate while she slept? Had they laughed as they watched her broken body mend itself together? Had they let her feel pain, just to see if she could?

Shepard claimed that she had no memory of those years, but had she only blocked them out so she could live with it?

We don't live with it, and that's the problem.

"Garrus? What's wrong?"

He blinked up at her, suddenly aware that he was crying deep in his throat. Her eyes were wide, concerned, but warm, as he remembered them from the first Normandy. Despite everything, the War, her injuries, the things they'd just seen, Shepard was holding it together, like everything was okay. Garrus shot up and pulled her into his chest, smelling the crisp tang of antiseptic in her hair.

"I'll be okay," he said. "A little rattled, but I'll be okay." He had to be, just like his father had to be. "Will you?"

"I will be," Shepard admitted. She hugged his waist. "It's been a long day."

Garrus sighed. "The longest."

Even the toughest people have something that haunts them.

This ties in to Garrus' parents' backstory. Aetius and Pallin served in the First Contact War/Relay 314. Pallin's mate, Phaedra did, as well. She was part of a recon squad that was captured by a human research team, and she met a horrible death there.