Spring came to the northern provinces six weeks after Hungan had stopped expecting it.
The northern coastal route had a specific relationship with seasons — they arrived late and left early and conducted themselves with the restraint of guests who knew they were not the primary occupants. The winter had been long in the way of northern winters, which was not harsh but sustained, the kind of cold that settled into the stone of things and had to be coaxed out slowly by the returning light.
He had been moving through the northern access points all winter.
Four through six had been as He Daomin predicted — smaller Vessels, narrower boundaries, the content modest compared to the third access point's Suqian's Shore comparable volume. Four had contained three objects and one book. Five had contained seven objects, all instruments, the connection-quality type. Six had contained nothing — an empty Vessel, the room without furniture, the walls and the shape of it present and the contents absent.
He had sat in the empty sixth Vessel for two hours before he understood that the emptiness was not a failure.
Someone had taken the contents before the cycling. Had removed them deliberately, carefully, with the knowledge that the Vessel would remain and the contents would not. The frequency residue of the removal was still in the stone — faint, very old, the trace of an intentional act preserved the way Hungan's presence had been preserved in the Qinglan Bridge's stone after a single morning session.
Someone had emptied the sixth Vessel before the first cycling.
Someone had known the cycling was coming — had known far enough in advance to remove the contents and take them somewhere.
He had sat with this for two hours and then he had come out and told Shao Peng and Shao Peng had written it down with the careful neutrality he brought to information that had significant implications he was not yet ready to process and they had continued north.
The seventh access point was ten days further along the coastal route — or had been, before the spring thaw made the coastal track impassable and pushed them inland to the provincial road and added four days to the journey.
He was not impatient about this.
He had learned, in the winter months of working through the access points with Shao Peng and Cao Renfeng and the occasional addition of Lin Suyin when the correspondence routes aligned and she could reach them, that the work had its own pace. The Vessels had been waiting for longer than he had been alive. They would wait four more days for a spring thaw.
"The seventh," Mage said on the fourteenth morning of the journey.
"Yes," Hungan said. "Today."
"You feel it," Mage said.
"Since yesterday," he said. "The ambient frequency changed. The fourth-dimensional reading is—" He paused. "Different."
"How different," Mage said.
"The first three access points," he said. "They had the quality of things that had been placed in the Vessels. Preserved. Maintained. The fourth, fifth, sixth — the same quality, smaller." He paused. "The seventh is not that quality."
"No," Mage said.
"It is not the quality of something placed," he said. "It is the quality of something that arrived."
"Yes," Mage said. Very carefully.
He thought about what he had written in the notation book after the Glass Sea. The entity moved through a Dimension Vessel and was changed by the passage. Something from the Vessel mixed with what the entity was carrying. He thought about Book One's final teaser — at the seventh access point something arrived that was not preserved.
"Something moved through this Vessel," he said. "From the outside. Not from the main layer — from further out. And it left a residue."
"Yes," Mage said. "That is what I believe."
"From where," he said.
"That," Mage said, "is what we are going to find out."
The seventh access point was in a coastal cliff.
Not dramatic — not the sea stack's natural architecture or the cave system's geological deliberateness. A cliff face on the northern coast's final significant headland before the land broke into the scattered islands of the far northern archipelago. The access point was forty metres up the cliff, accessible by a route that the fourth-dimensional perception made clear and the physical landscape made strenuous.
Hungan climbed it with Shao Peng below maintaining the safety line — they had developed this system at the fourth access point after Hungan had climbed something difficult without a safety line and Shao Peng had communicated his position on this with the specific precision he used for non-negotiable logistics.
The access point was in a horizontal crack in the cliff face — not the crack itself, the Vessel boundary ran through the crack's plane, the fourth-dimensional intersection accessible from within the crack's interior where the stone had opened to approximately the width of a person's shoulders.
He wedged himself into the crack.
He put his palms on the stone.
He opened the Vessel.
What he felt was not what any of the previous six had felt.
The Vessels he had opened before — Suqian's Shore and the six access points — had the quality of interiors. Spaces with walls and contents and the ambient frequency of what had been placed in them. The seventh Vessel had that quality too — the walls were present, the interior was present — but something had disturbed it. Something had moved through the interior from one side to the other, and the passage had left the Vessel's ambient frequency permanently changed.
Not damaged. Changed. The way a room was changed by someone sleeping in it — the presence of the visitor recorded in the stone's frequency, the specific quality of what had passed through leaving a residue that was both less than the original thing and more than nothing.
He followed the residue.
Not physically — with the fourth-dimensional perception, the expanded sense that had been developing since the Glass Sea and had reached, over the winter months of sustained access point work, a level of specificity he had not anticipated when it began. He could move within the Vessel's interior the way a hand moved through water — feeling without being, reading without taking, present in the perpendicular direction without leaving the cliff crack.
He followed the residue to the Vessel's far boundary.
The far boundary was different from any Vessel boundary he had encountered.
The near boundary — the access point side, the intersection with the ley line — had the specific quality of Jiuling's geology. The mineral composition, the fault line frequency, the character of a planet's interior expressed as a Dimension Vessel wall.
The far boundary was not that.
The far boundary had a frequency he did not recognise.
Not unrecognisable in the way of previous-world or first-iteration materials — those were old and distant but they were in the same family as everything else he had encountered. From the same planet, the same solar light, the same geological history. This was different in a more fundamental way.
Different physics, was the thought that arrived. The frequency on the other side of the far boundary was operating on the same principles as Jiuling's cultivated soul-fire — the same fundamental structure, the same participation quality, the same correct-framework register — but the specific character of it was from somewhere that had different stone and different light and different air than anything on this planet.
He held very still.
He listened.
What he heard was not a sound.
It was a signal.
Structured. Deliberate. Repeating at intervals he could measure — not the slow heartbeat of Ethism's deposits, faster, with the specific rhythm of something produced rather than organic. The way a struck bell repeated its ring differently from the way water repeated its movement — the struck bell had the quality of intention, of someone having picked up the bell and hit it with the understanding that it would produce a sound.
This signal had the quality of intention.
It had been repeating for a long time.
He felt the age of it through the Vessel's wall — the residue of the signal's passage was layered, each layer the record of one repetition, hundreds of layers deep. Not hundreds of repetitions. He could not read the interval precisely from the cliff crack, but the depth of the residue suggested the signal had been repeating since before the current world's founding.
Since before the Consolidation Wars.
Since before the Pavilion's first extraction.
Since before, possibly, the second iteration.
Something on the other side of this Vessel's far boundary had been sending a signal through it for at least two world iterations.
"Hungan," Mage said.
He was aware of Mage at the cliff crack's entrance — not inside the Vessel with him, present at the boundary the way it was present at the access point itself. Waiting.
"Yes," he said. "I hear it."
"You know what it is," Mage said.
"Not specifically," he said. "In category. It is a signal. Structured. Intentional. Very old." He paused. "From somewhere that is not this planet."
"From somewhere that is not this planet," Mage repeated.
"Yes," he said.
"And it has been sending for—"
"Since before this world's founding at minimum," he said. "The residue layers. I cannot count them precisely but the depth—" He paused. "Mage. This was sending when the first world was still alive. Before the first cycling. Someone or something was sending this signal into this Vessel while Yuanhuo was still here."
The cliff crack was very quiet.
The northern sea moved against the headland far below with the patient indifference of northern things.
"Then Yuanhuo knew about it," Mage said.
"Yes," he said. "Yuanhuo knew there was a signal. May have known what it was." He paused. "The sixth Vessel. The one that was emptied before the first cycling." He paused. "What if the contents were not taken away. What if they were sent through. Through the far boundary. Toward the signal."
"A response," Mage said.
"Yes," he said. "A response. Yuanhuo received the signal. Understood what it was. Sent something back through the Vessel." He paused. "And the signal has been continuing since. Still sending. Still repeating." He paused. "Waiting for what Yuanhuo sent to arrive, possibly. Or waiting for someone to receive the signal with sufficient frequency sensitivity to understand it."
The cliff crack.
The northern sea.
The signal repeating through the far boundary of the seventh Vessel with the patient persistence of something that had been sending for three iterations of the world.
"What do I do with this," he said.
Not to Mage specifically. To the question. To the specific quality of a situation that required more than he currently had — more knowledge, more understanding, more time to build the framework for what receiving this signal actually meant.
"You do what you always do," Mage said. "You receive what is there. Without rushing. Without imposing direction." A pause. "And then you tell people."
He breathed.
He received the signal.
He let it be what it was — structured, intentional, repeating, from somewhere that had different stone and different light and the same fundamental understanding of what soul-fire was.
He received it until he had received it completely.
Then he came out of the cliff crack and looked at Shao Peng below him on the safety line and the northern sea beyond and the spring light on the coastal headland.
He said: "I need He Daomin."
Shao Peng reached for his correspondence materials.
"I will send a dispatch immediately," he said. "Arrival estimate?"
"As fast as possible," Hungan said. "Tell him to bring the complete geometric model." He paused. "All of it. Everything."
Shao Peng was already writing.
"And Lin Suyin," Hungan said.
Shao Peng wrote.
"And Xia Shuang, if she can leave the institution."
Shao Peng wrote.
"And Mage—" He stopped. Mage was already there. Always there. "And Mage," he said anyway, because saying it was the right thing.
"Here," Mage said. "As always."
"Yes," he said. "As always."
He looked at the cliff face. At the crack where the seventh Vessel's access point was. At the far boundary where something had been sending a signal for three iterations of the world to whoever came with a frequency sensitive enough to hear it.
He heard it.
He was going to understand it.
He started down the cliff.