In the third year of Jianwu, heavy snow blanketed Nanyang Commandery. The elderly physician Zhang Bozu sorted through fragments of medical texts salvaged from the ruins. His blood-coughing hands still gripped a bone knife as he tried to mend the medical wisdom destroyed by the Qin fires. The boy Zhang Zhongjing brought him a warming astragalus and ginger broth, listening as his master described the secrets of survival hidden in plants and herbs. Ginseng, which hunters said could ward off the cold; dipsacus, which veterans relied on to mend broken bones; astragalus, used in everyday life by ordinary people: all were passed down by word of mouth, yet were in danger of being lost. The master and apprentice decided to use bamboo slips to preserve this knowledge. One would identify each herb's properties and flavors, the other would record its uses. Amid the blizzard, they gathered the first sparks of a flame that could carry forward the life wisdom hidden in plants.
