The Prince and Ai - 4. Chapter 4

Zhu Cilang
Courtyard, Eastern Palace, Forbidden City, Beijing
Eighth Month of the Seventh Year of Chongzhen (September 20^th 1634)

As the month passes, the palace notices my absence more keenly with each day. I do not attend the morning audiences, the ancestral sacrifices at the Imperial Ancestral Temple, or the Mid-Autumn Festival, and the empty place reserved for the crown prince becomes a subject of constant discussion.

Mooncakes had once carried secret messages, so I am denied one despite my imperial mother’s protests. The eunuchs who bring my meals and remove my waste whisper outside the workshop doors, and their reports become more elaborate with every retelling. They claim that the crown prince has stopped speaking, hammers metal until his hands bleed, and sleeps among unfinished wooden parts before rising before dawn to resume cutting, filing, and fitting components together.

Luo Yangxing’s men record every material that enters the workshop and every scrap that leaves it. They find nothing that can be called treasonous, only a five-year-old child who refuses the assistance of the palace craftsmen assigned to observe him, measures distances with string, marks angles with charcoal, and tests each component until it moves according to his design.

The reports do not remain with the Jinyiwei. Zheng Zhihui, the chief eunuch of the Eastern Depot, gathers the accounts of every servant under his authority and sends selected details beyond the palace through men loyal to Wen Tiren. Zheng Zhihui has spent years building his position through information, while Wen Tiren has promised to protect that position so long as the information continues to arrive.

Neither man understands what I am making. Their ignorance gives me the time I need, because Wen Tiren expects my confinement to end in embarrassment and Zheng Zhihui expects to profit from reporting the failure.

On the morning of the fourteenth day, I rise before the first gong and stand alone in the workshop. The air carries tung oil, sawdust, charcoal, and iron filings, while completed tools hang beside broken pieces that record each mistake made during the past two weeks.

Calluses cover my hands, and my forearms ache under demands that this five-year-old body was never meant to endure. Ai assures me that the pain comes from growth rather than injury, and my strength has increased several times since the confinement began, although I still do not understand every change occurring inside my body.

Ai has earned my trust through repeated proof. His warnings kept me safe while we built the mound furnace, which he called a “beehive oven”, for producing cleaner coke, refined iron inside a crucible, and shaped tools that could have crushed fingers or opened arteries if I handled them carelessly.

After washing my face in the basin left by the eunuchs, I dress in a dark blue robe with black trim instead of ceremonial yellow. I then walk into the eastern courtyard, where the completed machine waits beneath a heavy cloth.

I pull the covering away and expose a self-propelled, horseless vehicle with four wheels. Ai calls it a quadricycle, but the court will know it by a different name.

The frame is oak reinforced with iron bands at every joint, and four iron-rimmed spoked wheels support its weight. The rear wheels are larger than the front wheels, while a bronze-and-iron crankshaft sits between the rear axle and the standing platform. Two treadle pedals connect to the crankshaft through iron gears that I cut, filed, fitted, and oiled until every tooth engages without obstruction.

A storage compartment behind the platform can hold roughly two hundred and fifty jin. An iron steering bar turns the front axle through a pivoting joint, and layered leaf springs beneath the frame reduce the force transferred from the stone road into the wooden structure.

No horse stands before it, no servant waits behind it, and no shaft extends from the front for men to pull. Every part of its movement will come from the person standing on the platform.

To me, the vehicle is beautiful because my hands have made it real. Mozi had taught that survival depended upon effort, and this machine gives physical form to that principle through measured force, joined parts, and controlled motion.

Ai has reasons for directing my attention toward Mohism, just as capable ministers always had motives beneath their advice. Mohist thought offers practical methods that Confucian learning cannot provide by itself, especially in a dynasty weakened by famine, rebellion, corruption, and foreign invasion.

Emperor Wu of Han had elevated Confucianism to strengthen the imperial bureaucracy and weaken aristocratic rule by bloodline. I do not reject what Confucian order accomplished for earlier dynasties, but the Great Ming cannot survive by preserving forms after those forms cease to solve the problems before us. I have found myself gravitating away from my early thoughts of reform under Wang Yangming’s school of Mind against Zhu Xi’s dominant school of principle, at least in part.

I mount the quadricycle, place both feet on the treadles, and press down. The crankshaft turns, the gears engage, and the rear wheels move the vehicle forward without horse, ox, draft rope, or pushing servant.

For the first time, human legs drive a wheeled land vehicle through a continuous crankshaft rather than dragging its weight from the front. The machine carries me from the Eastern Palace and onto the Imperial Path of the Forbidden City under its own mechanical motion.

The outer court is already assembling. I hear officials taking their assigned places, ceremonial ornaments striking against belts, guards exchanging orders, and silk robes moving across the paving before I enter the main courtyard.

Horses stamp inside the imperial stables to the west, and incense from the Hall of Supreme Harmony remains in the cool morning air. Everyone present expects the established sequence of court ritual, and nothing in that ritual prepares them for a vehicle approaching without an animal.

The first men to see me are minor secretaries adjusting their court hats beside the passage. One lowers both hands and stares at the turning wheels, while another looks ahead of the frame for a missing horse and then bends to search beneath it for a hidden rope.

They remain in the road until I stop and greet them. When I ask them to move aside, they obey at once, but neither official resume their actions after I pass.

I press the treadles again, and the quadricycle gathers speed. The crankshaft maintains a steady rotation, the gear teeth transfer the force to the rear axle, and the iron rims cross the stone with a regular mechanical beat.

Conversation stops along the eastern colonnade. Civil officials turn first toward the sound and then toward the empty space in front of the vehicle, while several military officers step away from their ranks to gain a clear view.

A Ministry of Works clerk runs several paces beside me and studies the rear axle. He points at the moving crankshaft, seizes the sleeve of the man beside him, and says in a voice loud enough for half the courtyard to hear, “His legs are turning the wheels.”

The statement causes a second reaction stronger than the first. Men who had assumed some hidden servant or concealed cord was moving the frame now see the treadles rise and fall beneath my feet, and they understand that the vehicle converts the strength of one human body into continuous travel over land.

A censor lowers himself to inspect the underside as I pass, then rises with dust on his knees and calls out that there is no rope. Two military officers move into the path I have crossed and examine the wheel marks, while an elderly Hanlin scholar asks whether the machine can truly turn without stopping.

I answer by moving the steering bar. The front axle changes direction, the quadricycle completes a tight curve, and the rear wheels continue to drive the frame through the turn.

The sight unsettles the horses arriving from the stables. A bay mare rears against its tether, and a black stallion snaps its lead rope before three grooms bring it under control. The animals respond to a wheeled object that moves without the sound, scent, or visible labor of another animal before it.

The men respond with greater awe. They have seen handcarts pushed from behind, sedan chairs borne on shoulders, wagons pulled by teams, and wheelbarrows driven by exhausted laborers, but none of them has seen a person stand upon a vehicle and use repeated steps to make it carry him forward.

A purple-robed eunuch drops a ceremonial fan and leaves it on the ground. Another eunuch makes the sign used to ward against spirits, then stops when a Ministry of Works official declares that every movement can be seen and measured.

The official’s certainty does not lessen the wonder. It increases it, because the machine requires no miracle hidden from human understanding. Wood, iron, bronze, oil, and the strength of a child are enough to make it move.

As I continue across the courtyard, the implications begin to reach the military men. One asks how much grain it can carry, another asks whether soldiers can build it in field workshops, and a third watches the treadles while calculating how many horses an army might save during a campaign.

The civil officials reach different conclusions, but their attention is no less intense. Some whisper about provincial roads and tax grain, while others stare at the absence of a draft animal and consider a form of transport that does not consume fodder.

I keep my expression controlled, my posture upright, and my hands steady on the steering bar. The court must see more than a curious device; it must see a new way to use human effort.

The emperor has descended from the Hall of Supreme Harmony and now stands on the raised platform before the gate. Wang Chengen remains at his right hand, Luo Yangxing stands three paces behind him, and Wen Tiren watches from the edge of the gathering.

Zheng Zhihui stands several steps behind Wen Tiren despite his position in the Eastern Depot. His placement is improper enough to attract my attention, and the brief exchange between them confirms that the alliance revealed through Ai’s observations is active even here.

I bring the quadricycle to a stop before the platform. The gears cease turning, but the court remains silent because every man is waiting for someone else to explain what he has witnessed.

The emperor descends one step from the dais and studies the vehicle from front to rear. His gaze pauses on the empty space where a horse should stand, then moves to the treadles, crankshaft, gears, and steering joint.

He has seen costly mechanical clocks brought by Western missionaries and elaborate waterworks made by imperial craftsmen. Those devices moved in fixed places, while this machine has crossed the courtyard, turned under my direction, and carried a human body without external power.

The careful control expected of an emperor leaves his face. Genuine astonishment remains in its place, followed by hope that he does not yet attempt to conceal.

“What manner of thing is this?” he asks, and his voice carries across the courtyard. Every official leans forward because the answer will determine whether the court treats the machine as a craft, or a threat.

I dismount and bow with both hands before me. “Imperial Father, this is the Wooden Ox and Flowing Horse.”

Recognition spreads through the assembled scholars. He Rugi, Minister of Rites and head of the Hanlin Academy, stiffens before asking, “Is this the creation of the divine scholar from Your Highness’s dreams?”

“Yes,” I answer. “He gave me the name of the machine and said that learned men would recognize his work even if he did not speak his own name.”

He Rugi understands the intended conclusion at once. He kneels, bows three times toward Heaven, and raises his head with tears gathering in his eyes.

“I know the identity of the crown prince’s divine teacher,” he declares. “He is Zhuge Liang, the Sleeping Dragon, Marquis of Zhongwu and Chancellor of Han. Heaven has sent a divine minister to instruct the heir of the Great Ming.”

The name passes from one rank of officials to the next. Men who had spent decades studying the histories of the Three Kingdoms turn again toward the treadles and wheels, and the familiar title gives meaning to a machine that had seemed impossible only moments earlier.

He Rugi presses his forehead to the stone and continues in a trembling voice. “Oh great Kongming, Prime Minister of Han and strategist of the ages, this unworthy minister thanks you for instructing the crown prince. The ancestral altars of the Great Ming have not been abandoned, and the realm still possesses a path to survival.”

Dong Qichang remains standing for several breaths. His white beard trembles while he studies the joints, the wheel spacing, the motion of the crankshaft, and the marks left on the paving.

He then lowers himself beside He Rugi with deliberate care. “Marquis of Zhongwu, this old minister bears witness to the return of your spirit.”

The submission of two of Beijing’s most respected scholarly authorities changes the atmosphere of the court. Junior officials kneel in groups, several censors bow without waiting for instruction, and even men who remain standing lower their eyes toward the machine with open reverence.

The military officers do not kneel as quickly, but their restraint comes from calculation rather than disbelief. They inspect the cargo compartment, estimate the strength of the frame, and discuss whether a column of such vehicles could move powder, arrows, or cannons where horses were scarce.

A veteran officer of the Beijing Garrison keeps his arms folded while studying me. His expression shows interest rather than worship, and his attention remains on the machine instead of the claims surrounding it. I knew this man from my past life, and hopefully after today, will acquire his aide in this life.

The emperor stays on the first step below the dais. His initial astonishment deepens into urgent interest because he understands that even a small part of the legend could alter transport, supply, and war.

“Zhuge Liang,” he says quietly. “The Sleeping Dragon has chosen to instruct my son.”

I keep my head bowed and allow the court to consider the statement. The silence gives the emperor’s hope room to strengthen, and that change in the court places Wen Tiren in immediate danger.

Wen Tiren’s influence depends upon controlling access, interpretation, and suspicion. A divine teacher attached to the crown prince bypasses every channel he has spent years building, while a working machine gives physical evidence that no memorial or accusation can easily erase.

Zheng Zhihui moves closer to him and speaks without raising his head. I cannot hear the words, but Wen Tiren’s eyes shift at once toward the rear compartment, then toward the length of the courtyard.

Zheng Zhihui had reported every test conducted inside the Eastern Palace seen by servants, but he had not seen the quadricycle himself, either. He knows that I have moved the frame across short distances and thought it was merely an advanced cart, but he has never heard it can carry a burden or travel for many li like the legendary wooden ox and flowing horse.

Wen Tiren steps forward before the emperor can issue another declaration. “Your Majesty, this minister begs permission to speak, because the dignity of the throne requires that wonder be separated from proof.”

The emperor turns toward him, and the hope in his expression becomes guarded. “Speak, Grand Secretary, but choose your words with care.”

Wen Tiren bows, yet he does not look directly at the quadricycle. “This minister does not question Minister He’s learning or Grand Guardian Dong’s integrity. Their judgment carries great weight, but reverence cannot replace examination when a claim concerns Heaven, the succession, and the safety of the dynasty.”

Several officials raise their heads, displeased by the suggestion that their response has been careless. Wen Tiren notices, and urgency enters his voice despite his effort to maintain control.

“A wheeled frame has crossed level stone,” he continues. “That fact is remarkable, but it does not yet prove that the frame is the Wooden Ox and Flowing Horse. It proves only that treadles and gears can turn wheels under a light burden.”

A murmur of objection begins near the Hanlin officials. Wen Tiren speaks over it before the emperor can respond, because delay will allow the court’s awe to harden into belief.

“The histories did not praise Zhuge Liang for moving one child across a courtyard,” he asserts. “They praised a transport capable of carrying military grain across roads for great distances. If we name every ingenious cart a heavenly artifact, we lower the authority of the classics rather than honor them.”

His argument remains formally respectful, but his need to stop the recognition is now visible. He has expected a failed toy, and the moving vehicle has destroyed the position prepared through weeks of reports from Zheng Zhihui.

Wen Tiren turns slightly, and Zheng Zhihui understands the signal. The chief eunuch steps forward, kneels, and presses both hands to the paving.

“This slave has supervised the stores and servants as Chief of the Eastern Depot,” Zheng Zhihui says. “No full cargo test has been conducted under this slave’s observation, and the machine has not traveled beyond the inner palace. Grand Secretary Wen Tiren speaks only to prevent the court from reaching a conclusion before the object has been tested.”

Zheng Zhihui’s statement confirms their coordination more clearly than either man intended, but it was now a desperate gamble. Zheng Zhihui has not merely supplied palace information to Wen Tiren; he has revealed the fact that the Eastern Depot, which should serve only the Emperor, is cooperating with a high official. If there is no defense for his actions, Zheng Zhihui faces dismissal at best and summary execution for treason at worst

Wen Tiren seizes the opening. “Your Majesty, Chief Eunuch Zheng Zhihui possesses direct knowledge of the construction period. His testimony establishes that the claims now being made exceed every prior demonstration.”

He points toward the cargo compartment without unfolding his sleeves. “Let the vehicle carry iron rather than hope. Let it travel until weak joints split, poorly cut gears fail, or human strength reaches its limit. Let it compete against the methods already trusted by the empire.”

The court grows quieter because Wen Tiren has moved beyond cautious doubt. He now demands failure in public, and the force of his language reveals how urgently he needs it.

“If the machine cannot bear the burden recorded in the histories,” he says, “then it must be judged as a clever device made by mortal hands. If it bears that burden and surpasses man and horse, this minister will kneel before it and withdraw every objection and retire from service.”

He pauses, then adds another assertion before the emperor answers. “Until that test occurs, proclamations of heavenly intervention are premature, and officials who encourage them risk misleading the Son of Heaven.”

He Rugi’s face hardens, while several junior scholars protest under their breath. Dong Qichang remains kneeling, but he studies Wen Tiren with open disapproval.

Wen Tiren has gone too far to retreat. Zheng Zhihui keeps his forehead lowered, yet tension in his shoulders shows that he also understands the danger created by accusing senior officials of misleading the emperor.

Ai speaks within my mind in a calm voice. “His factual point is valid, even though his motive is not. A public load test was always necessary, and his alliance with Zheng Zhihui has provided witnesses who cannot later deny the conditions the quadricycle was created under.”

I understand the advantage at once. Wen Tiren intends to reduce the machine to a failed curiosity, but he has offered me a stage large enough to establish its value before the full court.

The emperor looks from Wen Tiren to Zheng Zhihui, then turns toward me. “Crown prince, can your vehicle bear the weight described in the old accounts?”

I bow again and answer without delay. “Imperial Father, out of respect for my teacher and the authority of the histories, this crown prince requests a complete demonstration rather than a brief test.”

I indicate the cargo compartment before continuing. “Let the vehicle carry one hundred and fifty jin of iron. Let a soldier carry the same weight on foot, and let a skilled rider place the same burden upon a standard pack horse.”

The officials begin calculating the comparison before I finish. One form of transport will rely upon a man carrying weight directly, another upon a horse carrying both burden and rider, and the third upon a man applying his strength through treadles, gears, axles, and wheels.

“We will complete twenty-five laps between the Meridian Gate and the Gate of Divine Prowess,” I say. “Each departure and return will measure roughly four li, for a total of one hundred li. Let civil officials, military officers, palace craftsmen, and the common people gathered near the outer gates witness every lap.”

Wen Tiren’s eyes narrow because the proposal exceeds the test he intended. He wanted a short trial that could expose an early break, but a measured contest before many witnesses can turn success into an uncomfortable political fact. He would lose prestige for challenging a divine artifact.

Zheng Zhihui lifts his head for an instant and looks toward Wen Tiren. The fear in his face reveals that he knows the machine will likely survive more strain based on my recommendations for this challenge. But it was too late for them to recant their objections.

Ai had once told me that boys slightly older than I am built and raced similar human-powered vehicles in western lands centuries later. Those future youths would race their self-made vehicles against one another in elaborate races. Thus, I intended to emulate this tradition.

I had heard that Mongols and other barbarian tribes are known for a culture of youths racing horses in their northern grasslands. Horse racing is not common throughout the Ming Dynasty in comparison, but annual races in Shanxi provide enough precedent for the court to understand the concept of a contest.

I add, “Luo Yangxing of the Jinyiwei should carry the iron on foot. He is strong, disciplined, and trained beyond the level of an ordinary porter, so no one can claim that the human comparison was chosen to fail.”

The emperor turns toward Luo Yangxing. The commander’s expression remains blank, but his jaw tightens because he did not expect his surveillance of the Eastern Palace to place him under the same public examination.

“Luo Yangxing,” the emperor says. “You will take part under the conditions named by the crown prince.”

Luo steps forward and kneels with exact formality. “This officer obeys, and this officer will not shame the Jinyiwei.”

His words acknowledge the command rather than me. When he rises, his gaze meets mine without warmth, apology, or curiosity.

The emperor asks, “Who will ride the horse?” He looks toward the military ranks, where several officers straighten in anticipation.

I have already considered the choice. The rider must be skilled enough that defeat cannot be blamed upon incompetence, and he must possess a temperament that allows the demonstration to remain a contest rather than a political quarrel.

“This crown prince requests Cao Huachun of the Beijing Garrison,” I answer. “His horsemanship is respected, and a horse under his control will provide a fair measure.”

Interest moves through the officers near the eastern colonnade. A broad-shouldered man with a weathered face steps out from their ranks and approaches the platform with the balanced stride of an experienced rider.

He kneels before the emperor and identifies himself. “This officer is Cao Huachun. I accept the race, and I will see that neither the horse nor the court is cheated by poor riding.”

Several military officers laugh quietly, and even the emperor’s mouth loosens for a moment. Cao’s answer reduces the tension without diminishing the seriousness of the test.

The emperor gives the order in a clear voice. “The crown prince’s vehicle, Luo Yangxing, and Cao Huachun’s horse will each bear one hundred and fifty jin. They will complete twenty-five laps for a total of one hundred li, and the full court will witness the result.”

The command moves through eunuchs, guards, clerks, and officers. Some attendants hurry to the imperial stables, others go to the Ministry of Works stores for iron ingots and reinforced packs, and messengers carry instructions toward the outer gates.

The gates are opened far enough for the gathered people to see the marked course without entering the forbidden precincts. News passes outward that the crown prince has built a land vehicle moved by human feet and intends to race it against a man and horse under equal burdens.

I remain beside the quadricycle with one hand resting on the steering bar. Officials who had first regarded it as a spiritual sign now approach its practical features, while craftsmen crouch near the wheels and study every visible joint without touching.

One military officer asks whether two men could power a larger version. Another replies that even a single machine capable of moving grain without fodder would matter during a siege, and a Ministry of Works official begins counting the number of iron fittings required for production.

Their discussion confirms that the machine has already changed the limits of what they consider possible. Even failure during the race will not erase the fact that a five-year-old child has crossed the imperial courtyard on a wheeled vehicle moved by his own legs.

The way the officials regard me also changes. Until this morning, many assumed that an unseen teacher supplied isolated instructions while servants completed the real work.

Now they have watched me operate the mechanism, explain the conditions of a test, assign qualified competitors, and place the reputation of my divine teacher upon a measurable result. A child guided by chance could not control the situation with this degree of precision.

He Rugi looks at me with reverence that extends beyond the claim of Zhuge Liang’s guidance. Dong Qichang watches with careful interest, while several military men study my decisions rather than my age.

Wen Tiren’s composure weakens for only a moment, but I see it. His challenge was based upon Zheng Zhihui’s reports, and I have accepted every condition while expanding the contest beyond his control.

Zheng Zhihui remains on his knees until the emperor dismisses him with a glance. When he rises, he avoids looking toward the Eastern Depot agents who now know that their chief has carried internal reports to a Grand Secretary.

Wen Tiren’s central weakness is his hunger for imperial favor and his willingness to build power through private arrangements. In my previous life, my father had eventually dismissed him as Grand Secretary, his enemies had accused him of corruption, and his property had been seized.

I had heard that Wen Tiren died impoverished and rejected by his family before the capital fell. His fate had already been severe, so I feel no need to hasten it, but I cannot allow his alliance with Zheng Zhihui to restrict the reforms required for the dynasty’s survival.

The iron ingots arrive first on wooden pallets carried by palace servants. Each piece bears the seal of the Ministry of Works, and clerks measure the three loads twice so that no faction can dispute the weight afterward.

Each competitor receives one hundred and fifty jin. I need two trips to transfer the ingots into the rear compartment because of the size of my arms, but the court still reacts when I lift a load that palace servants expect two children to carry.

Several military officers watch my hands and shoulders rather than the machine. Ai’s changes allow me to lift roughly one hundred jin for a short distance, although he claims that further development may eventually let this body handle several times its own weight.

Luo Yangxing approaches his iron without comment. He divides the ingots into two balanced packs, secures them to a wooden shoulder yoke, tests the knots, and lifts the full burden in one motion.

The muscles in his neck and forearms tighten immediately. Jinyiwei training gives him greater endurance than an ordinary porter, but one hundred and fifty jin is intended to exhaust a man over distance even when the weight is carefully balanced.

He looks toward me after adjusting the yoke. “Your Highness, this officer is prepared, and this officer hopes the machine proves worthy of the confidence placed in it.”

The words satisfy court etiquette, but his voice carries no goodwill. “Commander Luo, the course will provide the answer,” I reply before turning back to the cargo compartment.

He does not answer again. The cold silence between us contains more meaning than a public quarrel could safely express.

Cao Huachun’s horse arrives next, a sturdy black gelding fitted with a military pack saddle. Two grooms inspect the girth and straps while Cao oversees the loading of each ingot to ensure that both sides remain balanced.

He runs one hand along the gelding’s neck and speaks quietly until the animal settles beneath the unfamiliar weight. His ease with the horse confirms that they have worked together before, although a commander of the Beijing Garrison could have selected a more impressive mount for public display.

Cao notices me studying the gelding and smiles. “Your Highness expected a stallion with a bright saddle, perhaps?”

“I expected a commander to choose the fastest horse available,” I answer. “That gelding appears calm rather than fast.”

Cao pats the animal’s neck. “Speed wins a short race, but calm feet and a willing back carry weight for one hundred li. This old companion has brought me home from worse roads than those inside the Forbidden City.”

His confidence contains no insult, and I allow myself a small smile. “Then I am pleased Commander Cao has chosen a serious opponent.”

He laughs once and replies, “My horse may object to being called the opponent of a wooden cart, but I will explain the matter after the race.” The nearby officers laugh again, and the friendly exchange eases the horses and men around us.

Luo Yangxing remains silent to my left and does not acknowledge either remark. His refusal to join the exchange preserves the cold distance between us.

I mount the quadricycle and place my feet on the treadles. The added iron shifts the center of gravity toward the rear, but the leaf springs settle under the burden and the oak frame remains aligned.

I turn the steering bar left and right through a quarter arc. The front wheels respond without delay, and the pivoting joint retains the smooth motion achieved during eleven nights of filing, testing, and adjustment.

Behind my eyes, Ai reviews the engineering principles once more. He is not attempting to reassure me, because his attention carries the focused satisfaction of a designer about to see a concept tested under public conditions.

“The Song Dynasty had paddle-wheel warships driven by foot treadles,” he says. “Foot-powered vessels still operate on the Yangtze and Grand Canal, and some carry more than a hundred passengers or many thousands of jin of cargo. The principle already exists within Chinese practice.”

I adjust my grip on the steering bar while officials arrange themselves along the colonnades. Military officers gather near the starting line, palace clerks prepare lap records, and eunuchs position ceremonial screens to mark the turning points.

“European millwrights also developed crankshafts for mills, pumps, and bellows,” Ai continues. “Missionaries brought related designs east, but no institution combined those mechanisms with treadles, steering, suspension, and a four-wheeled land frame.”

Beyond the outer walls, the voices of the common people grow louder. Thousands may now be pressing toward the open approaches, drawn by reports that the crown prince intends to move one hundred and fifty jin without horse, ox, porter, or sail.

“The Han already used hand cranks in winches, wells, irrigation devices, and siege equipment,” Ai says. “None of the individual principles is new. The revolution lies in joining them into a transport system that multiplies human effort.”

I press one pedal down until the crankshaft engages, then hold the vehicle in place. The gears take the weight without slipping, and the loaded rear wheels remain ready against the stone.

“We have connected knowledge that remained separated in your original history,” Ai says. “This race will show the court that invention does not always require an unknown substance. It can begin by arranging known things into a new system.”

Pride enters his voice, and I feel the same emotion within myself. In my previous life, the dynasty had collapsed through war, hunger, political failure, and a long inability to convert knowledge into effective action.

Since returning to this body, I have needed proof that the Great Ming’s destruction was not inevitable. The machine beneath my feet provides the first proof because every part has been made from materials, skills, and labor already available within the empire.

The court’s deepest problem is not limited to an empty treasury, border war, rebellion, or corruption. Those crises become fatal when powerful men refuse to imagine solutions that do not already possess ancient approval.

Too many scholars treat the classics as a boundary rather than a foundation. They search the past for permission to preserve existing practice, even when changing conditions demand new institutions, new tools, and new forms of production.

The quadricycle now gives them a direct challenge. A human body has always possessed the strength in my legs, woodworkers have long known gears, smiths have forged axles and iron rims, and craftsmen have built springs, yet no one joined those elements into a land vehicle that carries its own driver.

I pedal toward the starting line at a controlled pace. The iron gears maintain their regular engagement, and the iron-rimmed wheels move the loaded frame while officials follow every rotation.

A group of Ministry of Works craftsmen bows as I pass, not because they accept the claim of divine instruction, but because they understand the labor required to make the mechanism function. Their respect matters to me because they can eventually build what scholars only describe.

I stop at the marked line. Luo Yangxing stands three paces to my left with the yoke across his shoulders and the iron loads hanging at equal height.

His breathing remains controlled, but his fingers grip the wood with unnecessary force. He looks straight ahead and gives no sign that we have ever spoken beyond the minimum required by imperial command.

Cao Huachun sits to my right on the black gelding. The horse shifts once under the burden, then settles when Cao lowers a hand to its neck.

Cao turns toward me with open competitive interest. “Your Highness, this officer wishes you strong legs, sound gears, and a fair course.”

I incline my head. “Commander Cao, this crown prince wishes your horse steady feet and enough pride to forgive defeat.”

Cao laughs and answers, “Then we understand one another. Let the best method of carrying weight win.”

Luo Yangxing remains motionless between the officials and the course. His silence is not friendly restraint, and I do not offer him the exchange I share with Cao.

Ahead of us, the full court watches the first human-powered land vehicle ever built within the Great Ming. Behind the gates, the people wait to see whether a child can make wood and iron surpass flesh, muscle, and centuries of accepted practice.