It took him nine days.

  Nine days of sitting in the Silted Bones with his legs crossed and his eyes closed.

  Wu Zheng watched with an expression that alternated between fascination and the specific anxiety of a man observing someone juggle live grenades.

  Nine days of treating his own body as an experimental apparatus, which it was, and his shattered dantian as a design constraint rather than a disability, which was either brilliant or suicidal.

  Chen Xi was prepared to accept either outcome as long as the data was clean.

  The problem, as he understood it: the dantian was a reservoir. Energy flowed in, was refined, and was stored.

  His reservoir was broken — cracked open, leaking from a dozen fractures, unable to hold anything for more than a few seconds before the contents drained away through the gaps.

  Every cultivator he had asked about (Wu Zheng was his only source, but the old man's knowledge was deep if disorganised) treated this as a terminal condition.

  A shattered dantian was the end. You could not cultivate without storage, the same way you could not fill a bucket with a hole in the bottom.

  Chen Xi did not think in terms of buckets.

  He thought in terms of turbines.

  A reservoir stores water behind a dam.

  A turbine doesn't store water at all — it processes a continuous flow, extracting energy from the movement itself.

  No storage required. The water enters, does work, and leaves. The system is never full and never empty. It is perpetually in transit.

  What if he didn't need to store Qi?

  What if, instead of trying to patch the broken reservoir, he built a system that processed Qi continuously — channelling it through a structured path that extracted usable energy from the flow without ever stopping it?

  The mathematics were not trivial. They were, in fact, the most complex fluid dynamics problem he had ever attempted, and he had once spent eight months modelling plasma containment for a tokamak reactor.

  The variables included: meridian diameter (which varied along each channel), junction point resistance (which he was measuring one painful experiment at a time), the energy's propagation speed (constant, thank God, or thank whatever passed for God in this place).

  Finally, the shattered dantian's own chaotic output, which was not zero — the fragments still resonated, still produced erratic bursts of refined Qi that dissipated uselessly because there was nothing to catch them.

  Unless you caught them in a vortex.

  A vortex. A self-sustaining rotational flow pattern, like a tornado or a whirlpool, where the energy's own momentum maintains the structure.

  The fragments' erratic bursts would feed the rotation.

  The rotation would create a low-pressure zone at the centre, drawing in ambient Qi from the environment.

  The drawn Qi would be processed by the rotation itself — refined through centrifugal separation, the denser, more usable energy migrating to the centre while the waste was flung to the periphery and expelled.

  This narrative has been purloined without the author's approval. Report any appearances on Amazon.

  No reservoir. No storage. A continuous processing engine where the shattered dantian was not a broken bucket but a set of turbine blades.

  He ran the numbers in his head. The mnemonic system groaned under the load — this was not what it had been designed for — but it held.

  He needed meridian routing that would support rotational flow. He needed junction points that could handle centripetal forces without rupturing.

  He needed an initiation sequence that would spin the vortex up from zero without tearing his channels apart in the process.

  On the sixth day, he asked Wu Zheng to send Qi into his palm again.

  "How much?" Wu Zheng asked.

  "Everything you can spare."

  "That could kill you."

  "Noted. Proceed."

  Wu Zheng sent the energy. Chen Xi directed it — not into the dantian, not along the standard circulation paths, but into a spiral.

  A tight, calculated helix that wound through six meridians he had mapped over the previous five days, each one chosen for its diameter, conductivity, and structural integrity.

  The energy resisted at first. Qi, it turned out, had opinions about where it wanted to go, and "in a circle" was not among them.

  He forced the first rotation through sheer concentration, which felt like pushing a boulder uphill with his thoughts.

  The second rotation was easier. The third was easier still. By the seventh, the Qi had found the groove — the path of least resistance that his calculations had predicted — and began to sustain itself. The vortex spun up.

  Ambient Qi from the Silted Bones — there was more here than Wu Zheng had told him, leaking from the ancient bones like radiation from spent fuel rods — began flowing toward the low-pressure centre.

  He felt it. Not as warmth or pressure but as clarity. As though a fog he hadn't known was there had thinned, and the world had sharpened.

  The vibrating fragments of his shattered dantian, which had been producing nothing but pain and noise for ten days, found the rotation and locked into it, their erratic bursts synchronising with the vortex's frequency like metronomes on a shared platform.

  The pain stopped.

  Not diminished. Stopped. For the first time since he had woken in this body, the broken thing in his chest was not screaming. It was humming. A low, steady, rotational hum, like a well-tuned engine.

  He opened his eyes. Wu Zheng was standing three metres away, his face doing something complicated.

  "What did you just do?" the old man said.

  "I built a vortex."

  "A what?"

  "A self-sustaining rotational energy processing system using my shattered dantian fragments as impellers and six primary meridians as flow channels. The efficiency is..." He paused. Measured the input rate. Measured the usable output. Ran the ratio. "Forty-one percent."

  "Forty-one percent of what?"

  "Of the ambient Qi I'm drawing in, forty-one percent is being converted to usable refined energy. The rest is waste heat and structural losses."

  Wu Zheng was very still. "The standard techniques taught in most sects achieve three to five percent. The Azure Dust Sect's core method, which I spent a hundred and forty years mastering, achieves eight."

  "Yes. Your methods are extraordinarily wasteful. I can improve this. The junction points at my elbows and knees are creating unnecessary turbulence. If I recalculate the flow path..."

  He closed his eyes again. Adjusted. The vortex wobbled, stabilised, and spun faster.

  The efficiency reading climbed.

  Fifty-three percent. Fifty-nine. He found a resonance — the specific rotational speed at which the dantian fragments' output synchronised perfectly with the ambient intake — and locked it in.

  Sixty-seven percent.

  He held it there. Pushed further.

  Found a secondary resonance at 72 percent but the structural load on his fourth meridian exceeded what he calculated its tolerance to be, and he was not willing to risk a rupture on day one.

  Sixty-seven percent would do.

  He opened his eyes.

  "Sixty-seven percent. I can likely reach seventy-two with structural reinforcement of the fourth meridian channel, but I'll need to strengthen the tissue first. Days, perhaps weeks."

  Wu Zheng sat down. Not the controlled descent of a man choosing to sit. The abrupt collapse of a man whose legs had made a decision without consulting him.

  "That's not possible," he said.

  "And yet."

  "You have no training. You have no master. Your dantian is destroyed. You have been alive — in this body — for ten days.

  And you have just achieved a cultivation efficiency that exceeds every recorded technique in the Nine Strata."

  "It's fluid dynamics," Chen Xi said. "It's not complicated. It's just... nobody here knows fluid dynamics."

  Wu Zheng looked at him. Looked at the bones around them. Looked at the bruised sky. Looked back at Chen Xi.

  "Who are you?" he asked. Not the casual inquiry of a first meeting.

  The genuine, slightly frightened question of a man who has just watched someone do the impossible and wants to know if they intend to do it again.

  Chen Xi considered several answers. The true one was long and implausible. The simple one was insufficient. He settled on the one that mattered.

  "I'm a physicist," he said. "And I think your world runs on the same rules as mine.

  You just haven't found them yet."