After the snow, Cyan Ox Ridge looked as though a handful of crushed silver had been scattered across it. Zhang Yifan carried a half-person-high bamboo basket as he waded through the pine forest. The tip of his nose was frozen red, but his eyes were as sharp as an eagle's. He remembered what his master had said: the seven-leaf returning-sun grass loved shade and feared the cold, and it would definitely grow under the roots of wind-sheltered, aged pine trees, with hedgehog droppings guaranteed to be within three chi of it—for those little creatures loved to nibble on grass roots, yet never dared to touch this poisonous medicinal herb.
"Found it!" The boy suddenly squatted down, brushing aside the accumulated snow to reveal three clusters of dark purple stems and leaves. Seven slender leaves were arranged in the pattern of the Big Dipper, and this was precisely the legendary "seven-leaf returning sun" capable of holding onto the final breath of a dying person. He carefully dug out the roots and stems with a bamboo knife, when he suddenly heard rustling noises from overhead. Looking up, he saw eight-year-old Huwa straddling a pine branch, holding a bulging cloth bundle in his arms, while snow from the treetops fell in soft flurries onto the tip of his nose.
"Well, well, Huwa, coming to steal my fleeceflower roots again!" Zhang Yifan deliberately put on a stern face, while his hand quietly pressed the mechanism button at his waist—an automatic roller he had improved using the "axle-wedge technique" from the Book of Mozi. Its jujube-wood shell was carved with the lifelike patterns of a smiling cyan ox, and at this moment it was hidden in the snowdrift five paces away. Huwa was so startled that his hands loosened, causing three mud-covered fleeceflower roots to tumble out of the cloth bundle. Suddenly, a crisp "creak" was heard as the rollers beneath the grinder churned up sparks on the icy surface, actually letting out a "moo" as they came charging right at him.
"A-A ghost grinder!" Huwa shrieked as he tumbled down from the tree, his bottom landing squarely on a soft cushion of dandelions Zhang Yifan had laid out in advance. It hurt so much that he grimaced, yet he didn't dare cry—just last month, he had seen with his own eyes this very grinder chase a wild peach-stealing monkey halfway across the mountain. At this moment, seeing the cyan ox's eyes glowing with golden light, he was so terrified that he hugged his head and burrowed straight into the snowdrift.
Zhang Yifan laughed so hard he couldn't straighten up. He fished a sheepskin pouch out of his bamboo basket, shook out some pale golden medicinal powder, and sprinkled it onto the scrape on Huwa's palm: "What are you afraid of? This is my improved 'earth-shrinking grinder', and it only chases little thieves who steal medicine." He suddenly lowered his voice, "But if you tell anyone that I stuffed a buzzer inside the grinder's belly, I'll turn your bed-wetting habits into a ballad and have Xiaoxiu spread it all over the village."
Huwa immediately clamped his mouth shut, staring in amazement at the wound on his palm that was rapidly forming a scab: "Brother Fan's medicine is even more miraculous than Grandpa Wang's!" Zhang Yifan ruffled his hair and stuffed the three fleeceflower roots back into the cloth bundle: "Remember, the three-flower berries in the eastern bamboo grove won't be ripe for another half a month. When the time comes, I'll teach you how to make candied fruit—but for now, you need to do me a favor." He pulled out a sketch of a "merit ledger" drawn on tree bark, "See this drawing? In the future, the wild boar meat your dad hunts can be exchanged for five feet of cloth."
Just as the two of them were talking, the mountain breeze suddenly wafted the Old Daoist's call: "Yifan—time to come back!" Zhang Yifan answered, then caught sight of a crooked, embroidered head of Huwa on Huwa's cloth bundle—undoubtedly Xiaoxiu's handiwork—and couldn't help adding, "Come over to my place tonight, and I'll teach you how to make wooden clogs that can slide on ice, ten times better than the clumsy shoes your dad makes."
When they returned to the Medicine Cottage, Zhang Xuanzhen was sitting on the threshold knocking out his tobacco pipe. Seeing five returning-sun grasses lying inside the bamboo basket, a trace of surprise flashed across his cloudy eyes: "Two more than your master expected." He suddenly stared at the dandelion fragments on Huwa's backside: "Yet the traps you set in the forest probably scared half the mountain's pheasants right into my snares?"
Zhang Yifan stuck out his tongue and pulled a dog-skin-wrapped fragment of Discourses on Salt and Iron from his embrace: "Master, look. 'The wise adapt to the times.' In this freezing weather, if we don't set a few mechanisms, how are we supposed to deal with these little monkey-troublemakers?" He suddenly remembered something, dragging a half-person-high Wooden Ox and Gliding Horse model out from the corner. Its ox mouth opened to spit medicinal powder, and its ox hooves were fitted with rollers so it could glide across the snow: "I improved it based on the 'Wooden Ox and Gliding Horse' you described. Delivering letters for hunters in the future will be faster than a dog."
The Old Daoist stroked the mortise-and-tenon structure on the wooden ox's body, then let out a light laugh: "You've truly inherited Mozi's essence, but these ox eyes..." He pointed to the two mica flakes embedded in the ox's head, which gleamed with a mischievous light in the firelight, "Why make them look like they're rolling their eyes?"
"That's the only way to scare off people who steal medicine!" Zhang Yifan proudly turned the mechanism. The wooden ox suddenly let out a "moo" and shook its head left and right, frightening Huwa into hiding behind Xiaoxiu. Xiaoxiu walked in carrying a bowl of hot ginger soup, and upon seeing the wooden ox's comical appearance, she laughed so hard that half the ginger soup spilled over: "Brother Fan is acting up again. Tomorrow, Huwa's mother will probably come looking for people brandishing a broom."
On the snowy night, the oil lamp in the Medicine Cottage cast three figures onto the window paper. Zhang Xuanzhen watched the boy hunch over the low table to draw the "merit ledger," while Huwa crowded close by to count counting rods, and Xiaoxiu wove a halter for the wooden ox with a red cord. Suddenly, he recalled his younger days of traveling far and wide, when he had grown accustomed to the quiet asceticism of Daoist temples, yet never expected that in this wild mountain village, he would end up teaching a disciple who turned the Book of Mozi and Book of Lord Shang into playful crafts.
"Come with me to the ancestral hall tomorrow." The Old Daoist spoke up suddenly, his tobacco pipe striking three crisp taps against the blue stone: "Hang your 'merit ledger' on the locust tree at the entrance of the village, and place this Wooden Ox and Gliding Horse in the grinding house—though let me make it clear beforehand, if the village elders scold you for 'abandoning the orthodox and rebelling against the path,' don't expect your master to speak up for you."
Without lifting his head, Zhang Yifan let the tip of his brush drop the final stroke onto the mulberry paper: "Master, rest assured, I've already prepared a 'chain of stratagems'—first, I'll have Huwa's father trade three tiger skins for three bolts of cloth, and then I'll ask Auntie Wang to exchange honeysuckle for an iron wok. Once everyone tastes the sweetness, naturally no one will scold me anymore." He suddenly turned his head, his eyes reflecting the leaping flames: "Besides, don't you often say 'Dao in Ants'? Isn't this merit ledger the very path trodden out by the ants?"
The Old Daoist froze, then threw back his head and laughed heartily, shaking the icicles on the crossbeam down in flurries. Outside the window, the snow had stopped at some point, and the snow accumulated on the pine branches bent the boughs, yet the eyes of the Wooden Ox and Gliding Horse could be seen gleaming brightly in the moonlight, as if they truly possessed a trace of spiritual breath. That night, the grinding house in Cyan Ox Village emitted the "creaking" sound of rotation, and some returning hunter happened to see two rows of comical ox tracks left in the snow, extending all the way to the century-old locust tree at the village entrance.