He found it by accident.
Which was the only way something like that could ever truly be found — not searched for, because you cannot search for what you don't know exists, but stumbled into when you were looking for something adjacent.
The archives beneath the western wing were not forbidden.
They were worse.
Forgotten.
No guards barred the narrow stairwell. No markings declared the space off-limits. It existed in the quiet category of places that power no longer needed but had never bothered to dismantle — sealed not by locks but by irrelevance, which was a more durable barrier than most.
Dust kept it better than soldiers ever could.
Aaron found the stairwell on a grey afternoon during one of his corridor walks, the ones he conducted under the cover of aimless childhood wandering. He had been mapping the western wing's lower level, filling in a section of his mental diagram that had remained incomplete for weeks. The corridor angled differently than expected — a degree or two off the palace's dominant geometry, enough that if you were only looking at beauty you would never notice.
He was not looking at beauty.
He descended.
The air cooled with each step, marble taking warmth back into itself as the light above thinned to pale slivers filtering down the spiral shaft. The walls changed texture as he went — from the palace's clean, dressed stone to something rougher, older, with mortar lines that ran deeper and a solidity that had nothing to do with impression.
Purpose-built. Built for function rather than awe, by hands that were not interested in awe.
At the bottom, a long low chamber. Dry parchment smell, the particular mustiness of documents sleeping through decades. Wooden racks bowing slightly under slow pressure. Scroll cases in careful disarray, their lAarons faded to near-illegibility.
Not curated knowledge.
Abandoned knowledge.
He moved along the shelves with the methodical patience he brought to everything that mattered, fingers trailing edges, reading lAarons where he could and inferring from context where he couldn't. Most of it was exactly what abandoned archives contained in every civilization he had ever studied — grain inventories made obsolete by three generations of changed administration, shipping manifests for trade routes that no longer existed, ceremonial records for occasions no one currently alive remembered.
Data past its functional life.
He almost left.
Then his hand paused on a scroll that weighed wrong.
Heavier than it should have been. The casing was different too — dark metal clasps instead of wood, the scroll material beneath thicker and textured in a way that registered as not paper and not parchment but something in between that he couldn't identify by feel alone.
He eased it open carefully.
The script inside was not Altissian. Not Imperial Standard. Not any court language he had encountered since rebirth or studied since in the palace library. The characters were angular, deeply incised, each stroke cut with a finality that ordinary writing didn't carry. The ink hadn't softened with age the way human calligraphy did — it remained stark against the material, defiant.
He knew the feeling of looking at something familiar before the mind has finished identifying why.
Dwarven.
The recognition arrived as instinct before certainty — a fragment of historical recall from another life colliding with what his eyes were reading. He had studied civilizations in his first life that built for centuries instead of decades, that carved permanence into stone because they understood that paper and policy were temporary and stone was not. Dwarven construction had always interested historians for exactly this reason: it did not decay the way human ambition did.
He leaned closer.
The shapes resolved from script into structure.
It was not a manuscript.
It was a map.
Lines layered over lines in geometric complexity that made him stop breathing for a moment — thick corridors branching into thinner ones, hidden intersections marked with angular notation, hollow spaces indicated inside walls that the palace above presented as solid. Staircases woven like roots beneath visible anatomy. Routes that went between the places everyone used and the places no one knew existed.
The palace had a second skeleton.
He sat down on a low wooden crate without noticing the transition from standing to sitting, the scroll spread across his knees, and stared at it for a long time.
The question that surfaced was not about the map.
It was about who had built what it described.
The old court stories — the ones mentioned in footnotes of the texts he had been steadily working through at a pace carefully calibrated to seem unremarkable — spoke of ancient builder-craftsmen who had laid foundations into the first Caelum estate that would outlast anything built on top of them. The stories had the quality of myth. He had read them with the scepticism he brought to myths, which was not dismissal — myths were data about what a culture chose to remember and how — but measured distance.
He was no longer measuring distance.
If dwarves had built this, the Diamond Palace was older than anyone currently living fully understood. Older than the histories that described its founding. Older, possibly, than House Caelum itself.
And far, far deeper.
He stayed until the light above shifted toward evening and the air grew cold enough to be unignorable. He did not feel the hours pass. He was encoding, not reading — running routes behind his eyes, laying them over his existing mental map of the palace above, identifying where hidden corridors ran parallel to known ones, where stairwells existed inside walls that his six years of observation had never flagged.
He had been mapping the palace's surface.
This was the map beneath the map.
He returned the scroll to its casing, placed it precisely where he had found it, and climbed back into the warmth of the corridors above. He needed to think before he acted. He needed to determine what this was, what it represented, and who — if anyone — should know he had found it.
He had three people he trusted with things that mattered.
He went to find them.
The courtyard was quiet in the late afternoon, the post-lesson hour when the palace's rhythm paused briefly before dinner preparations changed the pressure of the place. Tomo was on the bench near the fountain attempting something with a piece of string and two sticks that appeared to be either a complex knot or a failed attempt at a small structure. Shion sat nearby with a book, reading at a pace that suggested she was actually thinking rather than actually reading. Xeno stood at his usual edge of things, present and still.
Aaron set the scroll case on the stone bench without preamble.
Tomo looked up from his string. "What's that?"
"Something I found." He eased off the casing and unrolled the map carefully, holding the edges flat with two fingers. "Tell me what you see."
They gathered close. Tomo leaned in first, immediately, the way he did with everything — curiosity before assessment. Shion set her book down and moved with the deliberate pace of someone whose attention had been fully redirected. Xeno came to stand at Aaron's shoulder, the position he always took when something warranted evaluation.
Tomo's eyes moved across the surface for several seconds.
"This looks like it shouldn't exist," he said.
"Why?" Aaron asked.
"Because things that are supposed to exist don't get hidden in basement rooms. Things that are supposed to exist are framed and lit and have small cards beside them explaining their historical significance." He looked at Aaron. "Where was it?"
"Archives beneath the western wing. A room no one maintains."
"How did you find an unmaintained room?"
"I was mapping a corridor that didn't align with the sections around it."
Tomo looked at him for a moment. Then at Shion. Then back. "He maps corridors," he said, in the tone of someone confirming something they had suspected but not verified.
"We know," Shion said. She was already leaning over the scroll with the intensity she reserved for genuine problems. "The script isn't any court language. The structure is completely different — the grammar of the marks, the way they relate to each other spatially." Her finger hovered above the surface without touching. "It's not decorative. These aren't words at all, they're instructions."
"Instructions for what?" Tomo asked.
"Reading the map," Aaron said. "Notation. It tells you what the different markings indicate." He pointed to a cluster of angular marks near the upper portion. "These are — I think load-bearing points. Structural anchors. This one—" He moved his finger to a different cluster. "This indicates access. Entry points."
Shion looked at him sharply. "You can read this?"
"Some of it. Enough to understand what it is."
She held his gaze for a moment. The look she used when she was updating her model of a situation. "When did you learn Dwarven notation?"
He met her eyes. "I haven't. I'm pattern-matching against the map structure itself. The notation system is logical once you understand what the map is showing."
"And what is it showing?"
He tapped the scroll lightly, a single finger in the center where the lines were densest.
"The palace," he said. "All of it. Including the parts that aren't supposed to be there."
A silence landed.
Tomo broke it, which was consistent. "Dwarves built the palace?"
"Part of it. The foundation. Maybe more than the foundation." Aaron looked at Xeno. "Did you know?"
Xeno was quiet for a moment. Not the pause of someone who didn't know but the pause of someone deciding how much of what they knew was theirs to give. "My family's records mention old builders," he said. "Ones who worked the stone before the first Duke's time. The records are — fragmentary. My grandfather said the specifics had been allowed to fade because some of what they built was not meant for general knowledge."
"Hidden corridors," Tomo said.
"Among other things."
"What other things?" Shion asked.
Xeno looked at her. "I don't know specifically. The records use language that suggests significance without providing content. Which is a choice someone made deliberately."
"Someone wanted the existence of these paths known within certain families but not the locations," Aaron said.
"Or the details," Xeno said. "Yes."
Tomo sat back on the bench, arms loosely crossed, looking at the map with the expression he wore when he was thinking rather than reacting — the slower version, the one with the pause behind it. "So there are corridors inside the walls of this palace that don't appear on any official floor plan, built by people whose work has been deliberately let fade from records, and you found the only surviving detailed map of them in a room no one visits." He looked at Aaron. "And you're showing us."
"Yes."
"Why?"
The question was honest and deserved an honest answer.
"Because I trust you," Aaron said. "And because what I do with this information matters more than what I do alone."
Tomo's expression did the thing it did when Aaron said something that landed differently than expected — a brief recalibration, the surprise of being taken seriously in a register he hadn't anticipated.
Shion spoke before he could. "What do you intend to do with it?"
"Understand it first. Map the routes against what I know of the palace's visible layout. Identify where they go, where they emerge, what they connect." He rolled the scroll back into its casing carefully, protective. "After that — use the knowledge the way you use any knowledge about a system. Hold it until the moment it matters."
"That's very controlled of you," Tomo said. "Most people finding a secret map in a palace would at least go exploring first."
"I will go exploring," Aaron said. "That's part of understanding it. But exploration for its own sake wastes what the map is."
"Which is?"
Aaron looked at him. "Advantage. The palace looks the same to everyone who walks it. If there are paths that only we know, then we can move through it differently than anyone else. That's not a toy. It's a tool."
Tomo was quiet for a moment. "You said we."
"Yes."
"You said it before I did." He pointed this out with the particular tone he used when something mattered to him and he was approaching it indirectly. "You could have found this alone, memorized it alone, kept it entirely private. It would have been more secure."
"More secure and less useful."
"Why less useful?"
"Because I can't be in four places at once." Aaron looked at each of them in turn. "But if all four of us know the routes, we can move through this palace in ways no one can predict or follow. That requires trust, which is a vulnerability. But the capability is worth the vulnerability."
Shion was watching him with the quality of attention she gave to theorems. "You've already decided to memorize the whole map," she said.
"Yes."
"Tonight."
"Yes."
She looked at the scroll case. "Can we copy portions of it? The notation system — I want to study it properly. If I can work out the full grammar of it, there may be other documents in that archive that use the same script."
"We can't remove it from the archive. If it's noticed missing, the room becomes relevant and the room becoming relevant ends the advantage." He paused. "But you could come with me. Tonight, if you want. Study it in place."
Shion nodded once. Decided.
Tomo raised his hand slightly, the gesture of someone in a formal setting who had remembered they were not in a formal setting. "I also want to come."
"I know," Aaron said.
"Is that a yes?"
"Come if you're quiet."
Tomo put his hand down. "I can be quiet."
Xeno, who had been silent for the last several minutes with the quality of attention that meant he had been processing rather than disengaging, said: "The archive entrance — is it observable from the corridor?"
"Not directly. The stairwell is recessed. You'd have to be standing at the specific angle."
"Which means it's a controlled access point." Xeno looked at the scroll case. "I'll come. Not to study the map. To watch the entrance while you work."
The sentence was short and carried the complete weight of what Xeno was. Not an offer. A function being described, clearly and without ceremony.
Aaron looked at him.
"Thank you," he said.
Xeno nodded. The acknowledgment received and filed.
Tomo looked between the two of them. "You know, sometimes the two of you communicate in a language that has almost no words in it."
"Efficiency," Aaron said.
"Eerie," Tomo replied. But he was smiling.
That night, when the palace settled into its late quiet and the corridor traffic dropped to the minimum of night staff and distant guards, the four of them descended the western stairwell in single file. Xeno led, which no one had needed to discuss. Shion carried a small notebook and two stubs of charcoal. Tomo carried, inexplicably, a piece of string and one of the sticks from his afternoon project, which he declined to explain.
The archive was unchanged.
Dust and sleeping time and the particular quality of unvisited air.
Aaron unrolled the map across the crate he had used that afternoon and set two candles at angles that illuminated without risking the parchment. Shion positioned herself beside him and opened her notebook. Xeno returned up the stairwell to its midpoint, where he could hear the corridor above without being visible from below.
Tomo sat on the floor cross-legged and looked at the map for a long time without speaking.
"Tomo," Aaron said quietly, after several minutes. "What are you looking at?"
"The spaces between the routes," he said. "The rooms that aren't on the map. The ones the hidden corridors go around."
Aaron looked at him.
"Why?" Shion asked, not looking up from her notation work.
"Because if someone built corridors around certain rooms, those rooms meant something. You don't build a wall to avoid something that doesn't matter." He looked at Aaron. "Whatever those rooms are, they're more important than the corridors connecting them."
Shion's charcoal stopped moving.
She looked at the map.
She looked at Tomo.
"That," she said, with the careful tone of someone conceding a point they had not seen coming, "is correct."
Tomo looked quietly pleased. Not triumphant — the satisfaction of having contributed something real rather than having won something.
Aaron studied the spaces on the map that contained nothing. Blank areas inside the palace's geometry. Not empty space — enclosed space. Rooms the map indicated by their absence rather than their presence.
He had memorized the routes.
He had not thought about what lay at their center.
He began again.
Above them, the Diamond Palace breathed, beautiful and unaware.
Below it, four teens with candles and charcoal and one piece of string mapped the skeleton of something that had been waiting, in the dark, for someone patient enough to look.