Her name, according to the inscription on her breastplate, was Xu Ling.

  She had held the rank of Formation Commander in what the inscription called the Order of Precise Thought, which was a sect name that sent a specific kind of chill down Chen Xi's spine.

  She had been dead for approximately nine hundred years.

  Her skeleton was remarkably well-preserved — the residual Qi in her bones was still strong enough to glow faintly, a pale amber that pulsed at a slow, steady frequency.

  She had died facing the attackers, her arms positioned as though she had been executing a technique in her final moments.

  The technique had left scorch marks on the ground in a pattern that, when Chen Xi mapped it, resolved into a Fibonacci spiral.

  In her lap, protected by her body and the residual energy field that had kept her bones intact for nine centuries, was a manual.

  Not a scroll, which was what Wu Zheng had described as the standard medium for technique documentation.

  This was a bound book, made from a material that Chen Xi could not identify — thinner than paper, stronger than vellum, faintly luminous.

  The pages were covered in the mathematical notation he had found on the armour, and they were beautiful.

  He sat with the book for three days.

  The notation was not calculus, exactly. It was a system that had arrived at similar conclusions through a different evolutionary path, the way multiple civilisations independently developed writing without copying each other.

  The symbols were different.

  The conventions were different. But the underlying mathematical relationships — derivatives, integrals, differential equations — were identical, because mathematics is not invented.

  It is discovered. The number pi is the same in every universe.

  The relationship between a circle's circumference and its diameter does not change because you write it with different symbols.

  What the manual contained was a technique.

  This tale has been pilfered from Royal Road. If found on Amazon, kindly file a report.

  Not the vague, poetic technique descriptions Wu Zheng had recited to him — "breathe in the essence of heaven and earth, circulate the primordial breath through the nine palaces, condense the spirit into jade clarity" — but a precise, mathematically rigorous description of an energy manipulation method.

  It specified flow rates. It specified meridian paths by geometric coordinate rather than by mystical name. It included error margins.

  It was a scientific paper, written in a dead woman's notation, nine hundred years old.

  The technique described was a method for analysing and disrupting formations — the energy constructs that cultivators used as barriers, traps, and weapons.

  The core insight was elegant: every formation had a mathematical structure, and every mathematical structure had a critical point — a node whose removal would cause the entire system to collapse. The technique did not attack the formation's strength. It attacked the formation's logic.

  Chen Xi translated it. He adapted the notation to his own mathematical framework.

  He tested the principles against the formations he could observe — the boundary ward that sealed the Silted Bones was a formation, and Wu Zheng had described its general structure.

  "I can break the ward," he told Wu Zheng.

  The old man looked at him with an expression that had become familiar: the face of someone who had learned to take Chen Xi's impossible claims seriously because the impossible claims kept turning out to be true.

  "The ward detects cultivation energy," Wu Zheng said. "Anything above mortal baseline triggers the barrier. I've tested it. Many times."

  "I know. But the detection algorithm has a flaw. It measures static energy — stored Qi, the kind you'd find in a dantian. My vortex doesn't store energy. It processes a continuous flow.

  At any given instant, the amount of Qi 'in' me is negligible — it's all in transit.

  The ward's sensor sweeps at discrete intervals; if I time my approach to coincide with a low point in the vortex's cycle, I'll read as a mortal."

  "You'll read as a mortal."

  "The mathematics say so."

  "And if the mathematics are wrong?"

  "Then the ward kills me. But I've checked the numbers four times, and they're not wrong."

  Wu Zheng stared at the ward in the distance — a shimmer in the air, like heat haze, that marked the boundary of their prison.

  Seventy-three years. He had tested that barrier hundreds of times.

  He had thrown rocks through it and watched animals cross it and once, in a moment of desperate fury, thrown himself against it and felt the energy burn through his ruined cultivation like acid.

  "I can't follow you," he said. "My cultivation is too conventional. The ward will detect me."

  "I know. That's why I'm going to modify your energy signature first."

  "You can do that?"

  "I can try. The vortex core method can, theoretically, be adapted for external use — restructuring your Qi circulation to mimic my flow pattern temporarily. Long enough to cross the boundary."

  "Theoretically."

  "Yes."

  "How long will this take?"

  "Weeks. Maybe a month. I need to map your meridian system completely, calculate the modification parameters, and run simulations."

  He paused. "In my head. I don't have paper."

  "You're going to simulate a complete meridian restructuring in your head."

  "I have a good memory."

  Wu Zheng laughed. It was a sound like old wood cracking — surprised out of him, pulled from somewhere deep, a reflex he had nearly forgotten he possessed.

  He had not laughed in years.

  The dead in their rows did not react. They had heard it all before.