Fang Yuan enters a grey tent flying a gambling den couplet and walks past counters where fossils sell for five, ten, or twenty primeval stones depending on the row, each one possibly holding a Gu worm that sealed itself into rock after running out of food, the way a starved Moonlight Gu can turn to grey stone or a Liquor Worm spins itself a white cocoon. A shop clerk sizes him up as a curious student and steers him toward the cheaper counter, not expecting him to buy. ch. 40
From a memory of his past life, when he worked in and later ran his own rock gambling den, Fang Yuan recalls that on the caravan’s first night at this counter a lucky buyer once won a fossil with a purple gold luster for ten primeval stones and found a Mudskin Toad inside, later selling the Gu for a fortune. Counting twenty purple gold fossils on the counter and knowing he can afford at most seven of them once he sets aside money to live on from his ninety eight primeval stones, he weighs size, shape, and surface texture against what he remembers of a Mudskin Toad’s rough hide, ruling out fossils that are too flat, too small, or too smooth. ch. 40
No detection method can find a hibernating Gu inside a rock without killing it, so choosing rests on guesswork, experience, and luck alone, and the more prosperous gambling regions further east work the same way, where every village around Bai Tou mountain keeps a den of its own and the mega sized dens of Pan Shi, Gu Mu, and Cang Jing villages each carry a thousand years of history. Weighing his five hundred years of past life experience against the twenty candidates, Fang Yuan narrows his choice to six purple gold fossils that best match a Mudskin Toad, giving himself an eighty percent confidence that one of the six holds the Gu. ch. 40
