(A/N: I wanted an intermission chapter between the Alliance and Kingdom stuff, and this support-like chapter is what came out. It's character/relationship development, kind of reflecting Edelgard and Byleth's C support.)
They arrived at Garreg Mach shortly before nightfall, about a week and some days after leaving the Alliance's capital. Their coming to Garreg Mach was relatively quiet—a majority outside of her forces were led to believe they returned to Enbarr. That gave them some time to rest before moving into the Kingdom.
Nightmares haunted her when she tried to sleep. The dream itself alternated between her time beneath Enbarr and her faint memories of living in Fhirdiad; the two memories were presented as if one came after the other, torture and pain followed by childish naïveté and joy. It seemed so natural until the end—Edelgard was freed from the experimentation, only to be attacked from behind by the boy from Fhirdiad.
Her last breath in the dream was her first when she awoke. Edelgard sat up immediately, almost scared at first, then grew frustrated that it still bothered her. She should be stronger than this by now.
Still, the room seemed too small; it felt like that place, so she got out of bed and dressed enough to be comfortable outside. She left the dormitory, and out of curiosity went to the star terrace.
Feeling the wind was a small comfort, albeit one she wasn't quite willing to admit. Edelgard watched any of the soldiers that were still awake—a few were in the dining hall, as shown by a light glow coming from the building, and a few others were walking around the marketplace or guarding the entrance. It must've been close to midnight, but there was enough light for her to see vague shapes moving below her.
"I'm surprised you're still awake."
Edelgard tensed at the voice before relaxing again when she recognized it. She almost smiled when she turned around.
"I came outside for a bit of fresh air," Edelgard explained. "I suppose returning to the monastery brought back some memories. It hasn't been that long, yet this place is oddly nostalgic. And your reason?"
Byleth came closer to the edge, but didn't quite stand next to her. "I noticed you were up here and…wanted to check in on you, I suppose. Can I guess you had trouble sleeping?"
"…That really is my excuse for everything I do at odd hours, isn't it?" Edelgard mused. Byleth offered something similar to an amused look, a bit more easily read than usual. "But, yes, that's the case again."
She looked back out towards the soldiers still wandering, and Byleth stood to one end doing the same. By now it looked like the dining hall was empty, without any more light coming from the area. It gave a temporary illusion of being one of the only people still awake.
It took a few minutes before either of them spoke; it was Byleth that entertained wary conversation.
"Do you normally wander outside when you can't sleep? I know we've trained in the morning, but I haven't seen you awake this late."
"I have…something of a recurring dream," Edelgard explained, looking over at her. "They're very…frustrating; I can't control them."
"It's more of a nightmare, then?" Byleth asked.
Edelgard nodded. "A mix of nightmare and memory, yes," she admitted. "Stepping outside tends to help clear my mind when I wake up—I trained in the mornings during the academy because I couldn't do much else."
She turned back towards the precious few people still walking around. Edelgard could easily imagine staying here for most of the night, just standing there without anything else to consider.
"They're not nightmares," Byleth said after a moment, "But I used to have recurring dreams too."
"What were they about, if you don't mind me asking?"
"One was about fighting and war; the other, a girl sleeping on a throne. I stopped having them early last year."
"Why do you think they stopped?"
"…I'm not sure, to be honest. I know what changed, but it's hard to explain."
"I won't force you to say any more than that, then," Edelgard decided. Byleth cast her a thankful look, and after a moment Edelgard continued. "As for me, well… It's all blood. Corpses are dragged out, those who fell to madness bound to keep them from attacking the rest. One or two attempt escape but are murdered—the rest try to feign normalcy while begging those above to let someone survive."
She stopped talking about the dream itself fairly quickly, falling back on the memory of it instead. Edelgard glanced at Byleth and realized she must have noticed—she seemed surprised, then genuinely concerned. The mercenary turned towards her, and very carefully asked a question.
"You said these were partially memories?"
She didn't actually expect to hear some small bit of worry in her tone. Either Edelgard was getting better at recognizing Byleth's dulled emotions, or Byleth herself was growing easier to read.
Edelgard started to say it casually while looking at her, then choked on the first word. Instead, she looked off to the side and spoke quieter than she intended.
"Including myself, there were once eleven children of the previous emperor—I was the third youngest. All of us were brought beneath Enbarr and experimented on; some died by the experiments themselves, some by illness, and some were murdered or went mad. I watched and waited while all the others died and suffered; I was the only one who survived. I've had nightmares ever since—a constant reminder of why I've chosen to fight."
Byleth took a step towards her, hesitated, then stepped back again. Her expression went back to something Edelgard couldn't determine without watching more closely.
After another moment, Edelgard shook her head and put on a false smile. "Neither of us should be awake so late," she said. "We're meeting to discuss preferred strategies tomorrow, so it's best if we get some rest. Goodnight, Byleth."
She left without another word and returned to her room. It took her a few minutes before she convinced herself to lie down and once again attempt to sleep.