Her new prison was more comfortable than her old one. She had been expecting a ready-made jail cell, but the only thing that really set her room apart from an ordinary bedroom was that the door locked from the outside. And the window did have iron bars, but they had a crisscross pattern that made it look like a decorative choice. It also had frosted glass, so light could enter but no one could see inside, which Rhea was thankful for. Inside, it had an actual bed, which she was even more thankful for.
The guards were more attentive than her previous ones; it seemed that Edelgard and Hubert had assigned her guards who were more or less ambivalent towards her, knowing their job was to protect her as much as it was to keep her prisoner. She had even made small talk with some of them, and they weren't so bad. There was also a trained midwife, who was questioning her about what to expect from the pregnancy at the moment.
"If you age slowly, this pregnancy will not last decades, will it?" she was asking. Her name was Mae, and she had clarified that it was spelled that way when she first introduced herself. Mae did know she wasn't as human as she appeared to be, but if it bothered the woman, she didn't show it.
"No, the average Nabatean pregnancy lasts only six weeks longer than the average human pregnancy," Rhea answered. "Very young Nabateans age only slightly more slowly than human children. It's only during puberty, when we begin to develop our connection to our dragon forms, that our aging slows to a crawl."
"Interesting," Mae noted.
Rhea's face seemed to pale. "Oh no."
"What?" Mae asked. "What is wrong?"
"I'm going to have to put up with a teenager for centuries. Possibly as long as twelve hundred years," Rhea said, dread in her voice.
After a moment of silence, the two of them burst into laughter.
"I don't envy you that," Mae told her.
The two of them were interrupted by a knock at the door. "Doctor? Are you done with the physical? The Emperor wants to talk to the prisoner."
"Yes, I'm finished," Mae nodded. "You can call for me if you need me," she told Rhea, before leaving the room.
Edelgard entered the room after the midwife had left. "Good morning, Archbishop. Are you well?"
"I am being fed better, and I slept well last night," Rhea answered. "Did something happen that I should know about?"
"No, not much has happened on the war front that you would find interesting," Edelgard told her. "I wanted to talk about after the war, actually."
"I see," Rhea said. "I expect you want the Church to support your post-war plans?"
"Hopefully," Edelgard told her. "I won't try to force you. But it would be better for everyone if the war ended soon. If the bloodshed can be ended quickly, we should end it quickly."
"Provided that the resolution would not result in more war in the near future, I would agree," Rhea said, as neutrally as possible. Her gratitude toward the Emperor had not faded, but she still resented Edelgard for declaring war on the Church in the first place. "And it's because she attacked Garreg Mach that Byleth..." She shoved the thought down. Getting emotional would not accomplish anything.
She almost managed it. Almost.
"Once we draw Those Who Slither In The Dark out of their lair, I plan to return you to the Church and ally against them," Edelgard told her. "But because I do not trust you with political power, once they are defeated I want you and Seteth to step down from your positions within the Church. Live a quiet life with your family."
"Seteth did want to live as a simple fisherman," Rhea mused silently. "Very well, on the condition that I name my successor. I do not want the Church taken over by a political appointee. I will find one who will not call for rebellion against you, but I will not let you choose."
"Fine," Edelgard said. "I don't love the Church, but it is not my true enemy. My ultimate goal is to overthrow the Crest system, and the nobles who uphold it. You may not realize this, but the Crest system has caused much suffering-"
"You don't need to convince me regarding getting rid of the Crest system. I would welcome it," Rhea told her.
"Wait, really?" Edelgard asked. "But you supported the Crest system."
"Not by choice," Rhea said. "I despise the Crest system. If you can get rid of it, I would not be upset."
"Then why have you not done anything about it?" Edelgard asked, somewhat angrily.
"Suppose I were to change the Church's stance on Crests, and say that a Crest made someone no different from a normal human being. Do you think the nobles would take it well?" Rhea asked. "The Church does not have the power to make such a change by itself. The Knights of Seiros may be the best in Fódlan, but their numbers are too few."
Edelgard looked at her, clearly not satisfied by the answer. "Well, that won't be a problem for long. The Church may not have the power to enforce such a stance, but the Empire will. I want you to rescind the doctrine that teaches that Crest bearers are divinely chosen to rule. When we move against Those Who Slither In The Dark, you can claim they infiltrated the Church and changed its doctrines to suit their own purposes."
Rhea glared at her. "No."
"No? You won't rescind the doctrine?" Edelgard asked, angered.
"I will rescind the doctrine. I will not claim that it was the work of Those Who Slither In The Dark," Rhea insisted. "I will not allow the faith of the Church's followers to be wavered-"
"You won't allow it to be wavered?" Edelgard asked, nearly shouting. "All ten of my siblings lost their lives because of the emphasis placed on Crests! I was tortured because of Crests! Every day I prayed for the Goddess to save us, but she never did! My faith was pretty fucking wavered!"
"What?" Rhea thought. "What did they do to you?"
Edelgard allowed her Crest-or Crests, rather-to glow. "They implanted additional Crests inside us. I was the only one who survived. I..." the anger began to crack, and she broke down.
In that moment, Rhea finally began to understand. "Child..." she said. "She's trying to stop what happened to her from happening to anyone else...she's just like I was."
"I'm sorry," she said, reaching her arms out to Edelgard.
"Don't touch me. Don't you fucking touch me," Edelgard snapped, storming out of the room.
When Rhea fell asleep the night after the attack on the Holy Tomb, she dreamed of her mother's throne. Empty, as it had been ever since the Red Canyon.
"Mother...I'm sorry. I don't know what to do. I...I failed Fódlan. I could never measure up to you. I just don't know what to do. Without you..."
"You know, when I tried guiding humanity, it ended up resulting in a war that almost destroyed the world," a familiar voice behind her spoke. Rhea turned around, and saw the face she had been missing for eleven centuries. "I'd say as badly as you may have messed up, you have yet to top that."
"Mother..." Rhea spoke, tears in her eyes.
"Seiros," Sothis said to her, embracing her.
"Mother, I am so sorry. I deceived humanity, I...Byleth. I tried to force him to be you. I could never measure up to you...you must be so disappointed in me..." she choked out between sobs.
"Seiros, I'm not disappointed that you could not be me," Sothis told her. "I'm disappointed that you felt you had to try. You're my little girl, and I want you to be happy, and to shine bright."
"Aren't you going to scold me for everything I did wrong?"
"Why? You're doing a great job of that yourself," Sothis told her, producing a giggle from her despite herself. "You already know everything you did wrong; you don't need me to spell it out for you. Seiros, I love you. But you need to let go. I can't clean up your messes for you. You have to do it yourself. But you shouldn't try to do it alone."
"Byleth..." she thought. She had been drawn to him ever since he arrived. She had convinced herself it was because he was her mother's reincarnation, but she saw now that that was wrong, and she felt like a fool for ever thinking he was. Despite his grim exterior, she saw the way he lit up when he taught his students, the sarcastic way he answered stupid questions with a perfectly straight face, the way he loved to fish, the way he struggled to express himself...he wasn't completely unlike Sothis, but he was different in ways that she had overlooked yet seemed so obvious now. "He'll hate me..."
"He'll understand. I promise."
"Mother, I don't know if I can let go. I...I'm scared."
"Seiros," she said, looking into her daughter's eyes. "I will always be with you."
Rhea looked at the door. "Please, just don't end up like I did."