In the lingering summer heat of early morning, a scent of scorching hung over the threshing ground in Cyan Ox Village. Zhang Yifan crouched before a bamboo sieve, poking at the blackened dried yams with a thin wooden stick, his nose wrinkled in a scowl. Huwa’s mother had tried to imitate his "smoke method" for pest control, but she built her stove right in the path of the draft, practically roasting the half-dried herbs into charcoal.
"Brother Fan, you have to save us!" Huwa’s mother wrung her hands over the scorched yams and burst into tears. "Your Uncle Wang is heading to town tomorrow morning to trade for salt, and now the whole batch is ruined!"
The young man suddenly looked up and spotted three beetles with red spots on their backs crawling along the edge of the bamboo sieve. These were none other than the "granary-guard beetles" recorded in his Classic of Hundred Insects, which specialized in eating damp medicinal herbs, though at the moment they were dizzy and disoriented from the smoke.
"Don't worry, Auntie," he suddenly flashed a grin, pulling a gourd-shaped bamboo tube from his tunic. "I've already prepared 'insect-repellent sachets'—dried mint mixed with mugwort, plus a pinch of camphor powder. Hang these in the four corners of the granary, and it'll be ten times more effective than the smoking method."
Huwa’s mother took it with lingering doubt, only to hear a "crackling" sound overhead. She looked up to see Huwa straddling a locust tree, raining locust eggs down onto the threshing ground.
"You little rascal!" Zhang Yifan snatched up a bamboo pole and gave chase. Huwa laughed as he ran toward the herb field, but tripped over a trap he had dug himself the day before, tumbling headfirst into a pile of grass covered in dandelions.
The youth rested his hands on his hips, panting. "You dare scatter bugs into the herbs again? Last week you dumped all my spring-guiding insects into the pigsty, making Uncle Wang think the well had a pest infestation!"
Huwa rubbed his rear end and muttered, "Who told you to put springs on my clogs, making me fall into the mud pit..."
Before he could finish, he saw Zhang Yifan suddenly squat down, his eyes lighting up as he stared at the weed seeds clinging to Huwa's trouser legs. "Wait, these are seeds of the 'sticky-clothes weed'! I've been fretting over how to make 'tracking powder' for the hunters—if we grind these seeds into powder and sprinkle them on prey, a fox can be tracked from ten miles away!"
At noon in the Medicine Cottage, Xiaoxiu was helping Zhang Yifan sift camphor powder when she suddenly heard a strange "moo" echo from the backyard. Rushing over, the two saw an ox with a swaying wooden bell hung around its neck, a piece of cicada slough wedged inside the bell that refracted dazzling multicolored spots under the sunlight.
"Brother Fan is up to his mischief again!" Xiaoxiu covered her mouth, laughing. "What on earth did you put on the Old Cyan Ox?"
Zhang Yifan triumphantly spun the bell. "An improved 'Beast-Startling Bell'—the cicada slough gathers sound, the camphor wood bell scares away beasts, and combined with the sticky-clothes weed powder, hunters won't even need torches when hunting at night." He leaned close to the ox's ear. "Old fellow, help me test if this bell works!"
The ox suddenly tossed its head, and the bell clattered to the ground, startling a pheasant hiding in the firewood pile. Zhang Xuanzhen walked over from the herb field leaning on his cane. Seeing his disciple crouching on the ground picking up the bell with stove ash from Huwa's prank still clinging to his shoe heels, he spoke up:
"I hear you designed an 'anti-pest Eight Trigrams Formation' for the threshing ground? Mugwort in the *Qian* position, camphor wood in the *Kun* position—it's almost as if you're dressing the Book of Changes in medicinal herbs."
Zhang Yifan instantly sprang up, patting the grass leaves from his tunic. "Master, look, the bamboo sieves on the threshing ground are arranged according to the *Li* trigram, leaving the middle open for ventilation, and the four corners use granary-guard beetles as 'live alerts'—whichever way the beetles crawl tells you which corner is damp."
He abruptly pulled a roll of parchment from his tunic, covered in densely drawn distribution maps of various insects. "This is the latest revised edition of the Classic of Hundred Insects. I've even marked the 'grain-storage ants' inside the old locust tree hole; they're even better at hoarding grain than Huwa!"
The old Daoist chuckled softly, tapping his tobacco pouch against the millstone with three crisp snaps. "When you crouched by the granary last night observing the granary-guard beetles, did you skip dinner altogether?"
The youth scratched his head and smiled sheepishly. Remembering something, Xiaoxiu pulled an oil-paper package from her sleeve. "Here, your favorite locust flower cakes. I hid them inside the stove so Huwa couldn't steal them."
As twilight crept into the mountain hollow, Zhang Xuanzhen watched his disciple lying flat on a stone table sketching insect patterns, suddenly recalling the scene he had witnessed earlier that morning: after Huwa's mother used the insect-repellent sachet, the dried yams on the threshing ground gave off a faint medicinal fragrance, and a few granary-guard beetles obediently hugged the edges of the Eight Trigrams Formation, looking precisely like soldiers guarding supplies. This child always knew how to turn book learning into tangible, useful magic. Even the most ordinary insects became "troops" for governing the world in his eyes.
"Yifan," the old Daoist said suddenly, pointing to the bamboo-tube irrigation canal by the edge of the herb field, "if we compare Cyan Ox Village to a game of chess, you are the one holding the pieces. Now that the pivotal eye of the chess board has opened, how shall you play the next move?"
The youth's brush tip paused as he gazed at the starry sky reflected in the canal water. "The pivotal eye is in the 'people'. Hunter Li's hunting knife needs to be remade with steel, Aunt Wang's spinning wheel lacks an axle, Huwa needs to go to school and learn to read, and Xiaoxiu's red hair ribbon needs a new pattern—"
He turned abruptly, his eyes reflecting the flickering candlelight. "Master, you said 'Dao is in ants', but even ants know how to huddle together for warmth. If our Cyan Ox Village wants to live better, we must make every person a piece on the board, each with their own proper use."
The old Daoist froze, the fire in his tobacco pouch glowing and fading. He suddenly understood that his disciple had already broken free from the limitations of the "Dao of Medicine" and the "Dao of Commerce." In his eyes, the so-called "Dao" was simply a method to make life smoother and warmer—just like the spring-loaded clogs he made for Huwa, the pest-control formation he set up for the threshing ground, and the beast-startling bell he hung on the ox. Every single one started from the minutest details, allowing every living creature to find its proper place.
That night, Zhang Yifan lay atop the firewood pile, thumbing through the Classic of Hundred Insects. Xiaoxiu sat nearby, holding a newly sewn cloth doll of the Cyan Ox, when she suddenly heard Huwa's startled cry in the distance: "Brother Fan! Your 'pest control formation' attracted a wild hedgehog!"
The youth closed the book with a smile and stroked the wooden bell on the cloth doll. "Don't be afraid. Hedgehogs love to eat granary-guard beetles. This is called 'using insects to fight insects'—the Dao, you see, is right there in the hedgehog's sharp spines."
Moonlight washed over the threshing ground, illuminating the bamboo sieves arranged in the Eight Trigrams Formation, the youth squatting by the granary observing insects, and the matched pair of Taiji Jade Pendants inside the Medicine Cottage. Zhang Xuanzhen watched his disciple's swaying silhouette through the window paper, knowing instantly that the "Dao" belonging to this child was no longer merely a few stray phrases from ancient texts. Instead, it was like the mountain stream, winding through gullies and pressing forward through collisions, ultimately converging into a vast, roaring river of his own.
When the first insect chirp sounded, Zhang Yifan suddenly heard his master sigh from the inner room: "Tomorrow, pack the Book of Lord Shang and the Discourses on Salt and Iron into the wooden chest. The day after, accompany me to town to trade for some ink and brushes—your Classic of Hundred Insects should be printed into a volume. Who knows, the people in Chang'an City might be waiting to read it too."
The youth gave an affirmative reply, though he chuckled secretly in the firewood pile: his master might sound stern on the outside, but in his heart, he knew better than anyone that the Dao of Cyan Ox Village was long overdue to flow along the water inside the bamboo tubes, heading toward a much broader world.