Inside was actually a pill recipe!
However, given Lu Changsheng's attainment in the alchemy dao, he naturally grasped the purpose of this recipe at a glance.
The method of recording alchemy used within it belonged exclusively to Yan Yun. Had he not previously conversed with Yan Yun and read the other man's books on alchemy, he would have been completely unable to decipher its meaning.
Chapter 122