As a Chinese adoptee in St. Louis, teenage Daiyu often feels out of place. When an elderly Asian jewelry seller at a street fair shows her a black jade ring? and tells her that ? black jade? translates to ? Daiyu?? she buys it as a talisman of her heritage. But it? s more than that; it? s magic. It takes Daiyu through a gateway into a version of St. Louis much like 19th century China. Almost immediately she is recruited as a spy, which means hours of training in manners and niceties and sleight of hand. It also means stealing time to be with handsome Kalen, who is in on the plan. There? s only one problem. Once her task is done, she must go back to St. Louis and leave him behind forever. . . .