Yun Mei's numbers came through the relay like a diagnosis nobody wanted to hear.
"The output window at ten percent tissue health is five percent," she said. No preamble. No qualification. The researcher delivering data the way she always did — stripped clean, no padding, the math speaking for itself. "The accumulation threshold drops from sixty percent to sixty-two percent of current output. The extraction threshold rises from sixty-eight to sixty-seven. The window that was eight percent at fifteen percent tissue health is five percent at ten."
Wei Long was crouched in the waste channel twenty meters from the wellspring, the fold's damaged tissue thin under his palms. The relay consumed two percent of his fourteen percent processing budget. His perception bubble had contracted to four-point-eight meters. The fold's heartbeat came through the floor at sixty-three per minute, the feverish rhythm of an organism running beyond its capacity.
"Five percent window," he repeated. "The Crown's interface precision at fourteen percent processing is five percent."
"The precision and the window are matched. If you hit the exact center of the window, sixty-four-point-five percent output, the modification succeeds. Any deviation in either direction puts you outside the safe range."
"The probability of hitting the exact center with five percent precision tools?"
"Approximately fifty-fifty." The researcher's voice carried nothing beyond the number. Fifty-fifty wasn't an assessment. It was a coin flip. "You have an equal chance of landing inside the window or outside it. The precision resolution means you can't fine-tune beyond the five-percent increment. You're aiming at a target that's exactly the size of your smallest adjustment."
Fifty-fifty. Threading the needle had become flipping a coin. The margins that had been razor-thin at eight percent were now nonexistent at five.
"Options," Wei Long said.
"Increase processing capacity." Yue's voice through the bond, immediate. "Sixteen percent gives you three-point-five percent precision. The window widens relative to the tool. At sixteen percent, you have approximately two percent of margin on either side of center."
"Sixteen percent processing puts the Crown's dimensional signature above Zhao Feng's probable detection floor."
"Probable. Not confirmed. We don't know his instrument specifications."
"We don't know, which means we can't risk it."
"You're risking a fifty-fifty modification instead of risking detection."
"I'm choosing a known risk over an unknown one."
The bond vibrated with her disagreement. Not anger. Strategic frustration. The lunar spirit who could see both sides of the calculation and knew that both sides ended badly.
"Yun Mei." Wei Long's voice was steady. The steadiness of someone who needed the relay's two-percent processing cost to be worth the words traveling through it. "Is there another approach?"
Silence on the relay. The fold's heartbeat through the floor. The damaged tissue under his hands, warm and thin, the organism's biology holding together through whatever biological stubbornness kept living things alive past the point where the numbers said they should have stopped.
"How far are you from the wellspring?"
"Twenty meters."
"And the boundary tissue damage. You said the tissue is at approximately ten percent health. Is the damage uniform?"
"The echo snapshots show a gradient. The tissue health decreases as I get closer to the wellspring. The damage radiates from the wound site. At twenty meters, the tissue is approximately ten percent. At the wellspring itself, it could be lower."
"Or it could be exactly ten percent. The gradient might flatten near the wound because the tissue around the wellspring has been under chronic stress for eight months — long enough for the biology to reach a stress equilibrium. The tissue stabilized at its minimum viable state." Yun Mei paused. The pause of a researcher reaching for an idea that hadn't finished forming. "What if you don't modify the tissue at its current health?"
"I don't have a choice about the tissue's health."
"You do. The targeted conduit protocol delivers communicative-band energy to fold tissue through the Crown's interface. We designed it for remote delivery through the bridge pathways. But the principle works for local delivery too. Direct contact." Another pause, shorter. "If you put your hands on the boundary tissue around the wellspring and deliver communicative-band maintenance energy directly, the tissue receives biological support at the point of contact. Local reinforcement. The same way a targeted conduit strengthens the eleven-percent fold through the bridge, except you're not using the bridge. You're there. In person. Hands on the tissue."
"How much strengthening?"
"At fourteen percent processing, the Crown can deliver communicative-band energy through direct contact at approximately sixty percent of conduit efficiency. The tissue at ten percent health would begin absorbing the energy immediately. The conversion rate for communicative-band energy in stressed tissue is approximately forty-five percent. With continuous contact at those rates—" The scratch of a pen on paper. Quick calculations. "—the tissue health around the wellspring could rise from ten percent to twelve to thirteen percent in approximately twenty-five to thirty minutes."
"Twelve to thirteen percent."
"At twelve percent tissue health, the accumulation threshold drops back to approximately sixty percent. The extraction threshold stays at sixty-seven. The window widens from five percent to approximately seven percent. And at fourteen percent processing, the Crown's five-percent precision gives you one to two percent of margin on either side of center."
One to two percent margin. Not comfortable. Not the three-percent margin they'd calculated at the beginning. But margin. Room for imprecision without catastrophe.
"Twenty-five to thirty minutes of continuous contact," Wei Long said.
"Continuous. Your hands on the boundary tissue. Communicative energy flowing into the wound site. The tissue strengthening gradually under the biological support."
"I need to reach the wellspring first. Twenty more meters of navigation. Ten to fifteen minutes."
"Total time at the wellspring: ten to fifteen minutes transit plus twenty-five to thirty minutes reinforcement plus the reshaping operation itself, which at strengthened tissue takes approximately thirty to forty-five minutes." Yun Mei's pen scratched. "Total intervention time from current position: sixty-five to ninety minutes."
"Chen Bai."
The analyst's relay connected from the junction. Forty-two kilometers away. The communicative band carrying his voice with the clean efficiency that the protocol provided.
"Liu Chen's pulse cycle timing," Wei Long said.
"Every six hours. The last cycle ran approximately four hours and twenty minutes ago." Chen Bai's pen was audible. "The next cycle arrives in approximately one hour and forty minutes."
One hundred minutes. The intervention needed sixty-five to ninety minutes. The window between now and Liu Chen's arrival was wide enough for the lower estimate and tight for the upper.
"If the reinforcement takes the full thirty minutes and the reshaping takes forty-five, I'm at ninety minutes. Liu Chen arrives at one hundred. Ten minutes of margin."
"Ten minutes between completing the modification and Liu Chen's next pulse cycle." Chen Bai's voice was flat. "If the modification runs over, Liu Chen's apparatus activates while you're still working on the boundary tissue. The pulse cycle pulls energy through the wellspring with concentrated force. If you're interfacing with the tissue when the pulse hits—"
"The force transmits through the tissue into my hands."
"The force transmits through the tissue into your Crown interface. The pulse concentrator applies approximately thirty times the energy density of normal wellspring flow. At fourteen percent processing, the Crown's substrate isn't shielded for that kind of input. The pulse would overload the interface the way the feedback loop overloaded it during the lattice reading."
"Except this time I'm inside the fold, not in the junction where Yue could break the connection."
"I can still break the connection," Yue said. The bond carrying her voice with hard precision. "The bond doesn't require physical proximity to the substrate interface point. I severed the feedback loop through the bond's direct access to the substrate architecture. I can do it from inside the fold."
"How fast?"
"Point-three seconds from detection to severance. The same speed as the feedback incident."
"The pulse cycle lasts approximately four seconds," Chen Bai said. "Point-three seconds of exposure before Yue severs the connection. At thirty times normal energy density, point-three seconds of pulse exposure delivers approximately ninety times the energy that a standard conduit session produces."
"Survivable?"
"The substrate survived the feedback loop at seventy-five neural load. Ninety times conduit energy is approximately — " The pen calculated. "—fifty-two neural load equivalent. Below the feedback incident. Survivable. But damaging. The micro-lattice would record the pulse event. The substrate tissue would sustain stress. The effective capacity would drop."
Wei Long pressed his hands against the channel wall. The fold's tissue. The heartbeat at sixty-three. The damaged biology of an organism that had been living under Liu Chen's extraction for eight months, flinching from every touch, running a fever it couldn't break, broadcasting its pain through channels that nobody had been listening to.
The math was the math. Sixty-five to ninety minutes for the intervention. One hundred minutes until Liu Chen's next pulse. The lower estimate gave him thirty-five minutes of margin. The upper estimate gave him ten.
"I'm going to the wellspring," he said. "I reinforce the tissue. I reshape the wellspring. And I finish before the pulse."
"And if you don't finish before the pulse?"
"Yue breaks the connection at point-three seconds. I survive the exposure. I resume after the pulse passes and finish the modification."
"That adds another four seconds of Liu Chen's full extraction force tearing through the boundary tissue you're trying to repair." Yun Mei's voice was sharp. "The tissue I just told you to strengthen would be ripped back to ten percent or below by a single pulse cycle."
"Then I don't go over ninety minutes."
"Wei Long—"
"I don't go over ninety minutes. Close the relay. I need the processing."
The relay closed. The two percent of processing returned. His perception bubble expanded from four-point-eight meters back to six. The waste channel resolved in his awareness with the slightly better definition that two percent of a Crown's architecture provided.
"Ninety minutes," Yue said.
"Ninety minutes."
"The reinforcement timer starts when you reach the wellspring. Every minute of transit time eats into the margin."
He stood. The channel walls close. The damaged tissue thin. Twenty meters of helical descent through a dying organism's waste system, toward a wound that needed healing before it could be reshaped, against a clock that would bring Liu Chen's extraction force crashing through the boundary tissue in one hundred minutes whether the bearer was ready or not.
He moved. Not carefully now. Quickly. The fold's tissue flinching under his hands as he pushed through the constricted channel, the organism's reflexive contractions squeezing the diameter with each rapid contact. He didn't stop to let the flinches settle. The communicative-band frequency radiating from his palms as he moved, the non-hostile signal telling the fold's biology that the presence passing through its waste channel was not a threat, the message partially true and partially a lie because the Crown's bearer was moving through its interior with an urgency that a careful visitor wouldn't carry.
The tissue flinched and released. Flinched and released. The fold tolerating the rapid passage the way it tolerated Liu Chen's extraction — by enduring.
The channel opened. The third structural support. Beyond it, the final section of the helix. The boundary layer close. The temperature different here, the heat from the metabolic processor behind him replaced by something else. Something from outside the fold. Energy leaking inward through the wound, the wellspring's output channel carrying dimensional energy from the fold's interior to the mortal realm, and along the edges of that channel, the trace of whatever Liu Chen's apparatus did when it pulled.
The fold's boundary tissue. Twenty meters ahead. The wellspring wound waiting in the dark.
The clock running.
He moved faster. The channel walls rippling around him, the dying organism's muscles contracting and releasing in the wake of a bearer who was racing a deadline that the fold didn't know existed, toward a wound the fold couldn't repair, carrying tools that might or might not be precise enough to help.
Ninety minutes. Starting now.
