He went on a Sunday.
The maintenance access point was in the tower's northwest base, behind a growth of cultivated shrubs that were there for aesthetic reasons but had the practical effect of making the access panel invisible to anyone who wasn't looking for it. Lysander had described the location precisely. Aaron found the panel without difficulty.
It was not locked.
"No one has ever thought to lock it," Sirath observed, as Aaron eased it open and stepped into the tower's maintenance passage, "because no one has ever thought that accessing the tower this way would be worth doing."
"Security through obscurity," Aaron said.
"Security through the assumption that the interesting things are always behind the obvious door."
"Which they usually are."
"Which they usually are," Sirath agreed. "You are using the less obvious door because you cannot currently open the obvious one without alerting someone. A different situation would call for a different approach."
The maintenance passage was narrow and dark, lit by a faint bioluminescent growth on the stone that was either a mage formation or a natural occurrence — Aaron couldn't determine which immediately. He moved through it carefully, feeling the tower's spatial current around him. At rank four, the resolution of his perception was sufficient to notice something he hadn't expected: the tower's foundation was not uniform.
Different sections of the foundation had different spatial densities. Not randomly — in a pattern. A layered pattern that was, when he mapped it mentally against the formation diagrams in the Void Catalog, the blueprint for the bridgehead.
The foundation of this tower had already been partially prepared.
"Sirath," he said quietly.
"I see it," Sirath said. "The bridgehead preparation — someone has already begun it."
"When?"
"The formation modifications I'm reading through your perception are at least —" a pause. "At least one hundred and fifty years old. Possibly older." Another pause. "The Tenders. Someone among the Tenders understood the secondary function without knowing they understood it. They made modifications to the foundation formation that were consistent with the bridgehead preparation, without knowing that's what they were doing."
"How is that possible?"
"Someone gave them instructions," Sirath said. "Sufficiently indirect that they wouldn't know the full purpose, but correct in their specifics." He was quiet for a moment. "I think — I think I may have been more thorough than I remembered."
"What do you mean?"
"When I told the first Tenders what to do, I told them to maintain the network. But I may have also —" He paused. "I was very thorough, in the years before the Shattering. I knew I might not survive it. I may have given instructions that I didn't fully remember giving. Instructions layered enough that each generation of Tenders would receive only the piece they needed." A very long pause. "Like a letter written to be opened in stages."
"You planned it," Aaron said.
"I planned something. Whether it was exactly this — whether it matches what I intended three thousand years ago — I genuinely don't know." His voice was careful. "My memory of the last days before the Shattering is incomplete. The Shattering itself disrupted a great deal."
Aaron moved through the passage toward the tower's central foundation chamber. The spatial density increased with each step — the bridgehead formation's concentration. By the time he reached the chamber, the air was so dense with spatial element that it pressed against his skin like water.
The chamber was circular, roughly five metres in diameter, with a ceiling too high to see clearly. The formation was in the floor — carved into the stone, not with the fine precision of the crystal artifact but with the monumental precision of something meant to last and withstand everything that might be thrown at it. He crouched and looked at it.
Three thousand years of weather and time and human foot traffic above it, and the formation was as clean as the day it was carved.
"The preparation is at approximately forty percent," Sirath said, reading the formation through Aaron's perception. "The sections the Tenders modified brought it from the original's baseline to forty percent. The remaining sixty requires —" A pause. "The remaining sixty requires direct spatial manipulation at rank four minimum. It cannot be done through instruction. It requires a practitioner in this room, working with conscious knowledge of what they're building."
"And the time estimate?" Aaron asked.
"At rank four, with the crystal: three months, working carefully. Four to five months if we want to be completely certain of each stage." He paused. "There is a complicating factor."
"There always is," Aaron said.
"At sixty-five percent preparation, the formation will begin generating a detectable spatial field from the tower's exterior," Sirath said. "Subtle — anyone without spatial cultivation would not notice it. But someone with spatial cultivation who knows what to look for would register an anomaly."
"The watcher," Aaron said.
"If the watcher has spatial cultivation — yes."
"And if they don't?"
"Then the field is undetectable to them. The risk is proportional to their cultivation type." A pause. "We don't know their cultivation type."
Aaron sat in the chamber floor beside the formation and thought.
The formation under him was alive in the way that ancient, correct things were alive — not with the warmth of a person but with the settled certainty of something that knew its own function and had been waiting to perform it. He could feel it through his palm on the stone. Patient. Ready.
Three thousand years of waiting.
"I'm going to start now," he said.
"You have an hour before the maintenance staff does their Sunday check," Sirath said.
"That's enough for the first stage." Aaron placed his hand on the formation's closest active node — a point at the chamber's edge where the preparation was already at sixty percent and needed only the next layer to advance. "Walk me through it."
"Place the crystal against the node first," Sirath said. "The amplification matters at this scale."
Aaron placed the crystal against the stone. It warmed immediately — not the gradual warming of attunement but the immediate response of recognising a matched formation. The crystal's lattice and the chamber's formation were designed to work together. The crystal was designed to work in this room.
He had built the crystal without knowing that.
"Sirath," he said.
"Yes?"
"The crystal. The formation in the lattice." He looked at it against the stone. "You designed both. The crystal formation and the chamber formation." He paused. "You gave me the design for the crystal at the beginning of the artifact project. You said it was what the communication required."
"Yes."
"But it also interfaces with the bridgehead," Aaron said. "You knew it would."
A long pause.
"Yes," Sirath said.
"You didn't tell me that."
"No." His voice was very quiet. "You needed to build it for the purpose you understood. If I had told you the full function before you understood the communication need, you would have built it thinking about the bridge instead of thinking about the communication. The crystal needed to be built correctly for the communication function. The bridge function would follow from that." He paused. "I was not withholding information maliciously. I was — sequencing it."
Aaron sat with this for a moment.
"I believe you," he said. "And I'm going to ask you to stop sequencing it."
A pause.
"Going forward," Aaron said. "Tell me what I need to know when I need to know it. Not before, if the timing genuinely matters. But don't hold things because you think you know better than I do how to process them." He paused. "I understand you've been doing this for three thousand years and I've been doing it for eleven. But it's my life and my choices, and I need to make them with as much information as I can get."
A very long pause.
When Sirath spoke, his voice was different. Quieter. Something in it that Aaron hadn't heard before — something that was not quite apology, because apology required acknowledging a simple wrong, and this was more complicated than that.
"You're right," Sirath said. "I have been — sequencing things in the way I always taught. Because for three thousand years it was a teaching relationship and I was the one with the information and you were the student." He paused. "You are still a student. But you are also more than that, and have been for some time, and I have not fully adjusted." Another pause. "I'll tell you what I know when I know it. I'll do my best."
"That's all I'm asking," Aaron said.
He placed his hand on the crystal against the node.
"Walk me through the first stage," he said.
"Begin by extending your spatial perception through the crystal into the formation's active layer," Sirath said, and his voice was — different, now. The same precision, the same expertise, but with something looser in it. The voice of someone who has stopped carrying something.
Aaron extended his perception.
The formation met him.
For the first time in three thousand years, the bridgehead stirred.
Not dramatically — no light, no sound, no visible change in the stone. But in the spatial field of the chamber, something shifted. A forty-percent preparation became forty-one.
Small. Specific. Real.
He worked for fifty minutes. When he heard the distant sound of the maintenance staff on the passage stairs, he withdrew his perception, picked up the crystal, and moved smoothly back toward the access panel.
He emerged into the academy grounds in the late morning light.
The tower behind him was the same as always: silver, tall, catching the sun.
But he could feel it differently now. He could feel the formation in its foundation, the way you can feel the structure of a building in its walls when you know what to look for.
Forty-one percent.
He had two months, approximately. And the remaining fifty-nine percent to go.
"One problem at a time," he said quietly.
"One problem at a time," Sirath agreed.
Aaron walked across the campus toward the cultivation garden, where Sylvia was waiting with a question about the artifact refinement project, and Blake was sitting with a new gate configuration he wanted to show someone, and Ryan would arrive from his pattern-monitoring session in approximately twenty minutes.
The morning was clear and bright.
The tower stood at the campus centre, patient and old.
The formation in its foundation counted forty-one percent and waited for forty-two.
The work went on.