Li Muchen said, "The poison afflicting Elder Qian appears on the surface to be lodged in the bone marrow—a poison that has penetrated to the marrow. Yet its root cause does not lie in the marrow at all. The marrow connects to the brain and is stored within the soul. To put it plainly, this is a form of soul sorcery."
"Soul sorcery?"
"That's right. Soul sorcery originated as pure sorcery, but over time it evolved, and certain types of soul sorcery came to exist somewhere between sorcery and poisoning. Elder Qian's affliction is precisely of this kind. Because it straddles the two, soul sorcery is exceptionally difficult to cure. Ordinary sorcery can banish its malevolence but cannot remove the poison, while ordinary medicine can only disperse the poison lodged in the meridians without being able to rid the body of its evil nature. For Elder Hu to recognize that the poison was hidden in the marrow and to conceive of using acupuncture to guide the vital energy and counteract the poison—that is already quite remarkable."
Chapter 83