Sam Kuen, a traditional herbalist by trade, based on Nelson Street under the sign “At the root of Tang Kuei”, is a typical Chinese trader – open 6 days a week, 18 hours a day and present behind his very counter even with a high fever – but he has been absent from his shop for more than ten days, according to a fat si's informant. A simple routine investigation or once again the opportunity for them to confront a Chinese legend and intervene to restore harmony under Heaven? Translated from the back of the book.