Here is my prompt response. In case its not clear this is just after Nate's joining.
I spent way too long trying to find the texts and locations of the codex entries you find in the basement. I'll have to go by memory, so forgive me if I'm wrong.
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His mother had always told them to stay out of the basement. Nate was reasonably sure it hadn't been inhabited by darkspawn and undead in those days, but one never knew.
Things were different now, very different. His father dead, murdered by the very wardens he'd now joined. Been conscripted to join. Given a choice between death and conscription, if he'd actually had a choice, he'd have chosen death.
The Warden Commander hadn't allowed him the choice. So the Joining it had been.
It seemed his life had been spared by the very people who'd killed his father and destroyed his family. Was that irony? Or merely the Maker's idea of humour?
The Order that had killed his father. The Commander was Orlesian, more irony, and newly arrived in Ferelden. From what he'd discovered, only the dwarf, Oghren, knew anything first hand about the events of the Blight. Asking him about it hadn't proven enlightening. The dwarf had told him he was the wrong person to ask. Who was the right one if not Oghren? The Hero of Ferelden perhaps? The curiously absent Warden of legend?
Pity he hadn't had the chance to face her instead. One day perhaps, if he lived long enough, he would.
He could admit to himself that thus far the Commander had disproved everything he'd heard about both wardens and Orlesians. She was reasonable, thoughtful and seemed to have something resembling a sense of honour. When Samuel had told him Delilah was alive, Lilibeth had agreed to search Armaranthine for her. Not an empty promise either, they'd found his sister on the very next trip they'd made.
Now here he was following his new Commander down into the Basement of the Vigil. The basement his mother had warned him against.
Not just him of course, but also Oghren and Anders. He'd reserve judgement on the mage for now. His first impression wasn't favourable but he'd yet to see him in battle. It would be interesting to see if he stopped talking then or if even fighting darkspawn wasn't enough to shut him up.
He found the first note in a small storage room. They'd gone in to check for darkspawn and found a group of shrieks. Off all the darkspawn he'd seen, Nate found those the strangest. They'd dispatched them easily, leaving them free to explore the room. Anders and the Commander had moved to investigate a statue of Andraste when he'd seen it. Just near the bottom of the stairs beside a bookcase.
A quick glance at the others told him they were occupied, so he bent quickly and picked it up. The handwriting wasn't familiar but it was addressed to his father. One word stood out 'Cousland' and he quickly tucked it away in his pouch. He'd read it later but for now, it might be best if was kept to himself.
Having found one, Nate wondered if there'd be more. Perhaps this was a way to learn more about his father and what had happened during the Blight.
He found the other note near the tunnel to the Deep Roads. He'd almost missed it, distracted by finding Adria like that. A ghoul. It was, horrible. His companions had shown a surprising amount of empathy, particularly Anders. Something to consider.
They'd had to kill her. Adria and those unfortunate souls with her. All tainted by the darkspawn and beyond saving. As much as he might want to save them, Nate accepted that it wasn't possible.
In the brief quiet of the aftermath he'd seen the pile of books and the papers hidden under them.
This note he didn't read, just put away for later. Something in the tenor of the first note told him he'd best study them when he was alone. Would they give him comfort that his father had acted in what he'd thought were the best interests of Ferelden? Or only serve to disillusion him further about the father he'd once worshipped?
Delilah had told him, things, that disturbed him. Things she'd said their father had done. Things she'd witnessed. It was difficult to believe it, but believe it he must. His sister wouldn't lie to him about this, he knew that. Still it was, difficult.
Suppressing a sigh Nate turned back to follow the others and found Anders watching him. Had he seen him take the note? Tensed he waited. After a moment or two the mage lifted an eyebrow and nodded. What did that mean? That he'd keep this secret or was he simply acknowledging that they'd survived another fight?
Uncertain, Nate returned the nod and after a glance towards where the Commander was talking to Sargent Maverlies, Anders came over to where he was standing.
"This must be difficult for you." Of all the things he'd expected him to say, it wasn't that, not in such a serious tone. Thus far the mage had been a lot of things, serious not being one of them.
"It is, yes." Nate kept his voice soft and noticed Anders did the same. "I appreciate your concern."
"Well, we depend on each other don't we? The dwarf is drunk most of the time. I think if you stood in the wrong place, he'd take your head off without realising."
The truth of that made Nate smile. "What about the Commander?"
"From what I can find out, our lovely Commander expects to be reassigned once this mess is sorted out." The kitten hiding in the mage's pack mewed, and he scooped it out. "I appreciate her gift but its early days yet. Still a while to go before we'll know if we can trust her."
"We?" Unable to resist that soft fur, Nate gently rubbed the kitten’s head. "I'm the only Howe I see here."
"True. I'm not a Howe but I am from Highever. Call it neighbourly concern."
"Highever?"
"Hmm. I was born there."
"I see." Nate managed another pat before the kitten was once more safe in the pouch. He wanted to ask if Anders had seen him take the notes, if he intended to tell Lilibeth. "Anders." Anders smiled and shook his head.
"Didn't see a thing." Removing his staff he prepared to follow the Commander into the Deep Roads. "Your secret is safe with me Howe."