More people are dying from small pox, which prompts the Emperor to give Jiu Ling only 7 days to find a cure. She uses the scabs from the cured cows infected by smallpox as a potential inoculation to save the people, but it must first be tried on a willing subject. Zhu Zan volunteers, worrying Jiu Ling as she cannot predict the effect on him and that it may result in his death. (Source: frankly at MyDramaList)