I wish this book had been just that tiny bit better. The multiple (or even as in this case just dual) pov narrative seems to be the structure-du-jour these days, and can be effective, or it can have pitfalls. One important aspect is sustaining interest in both, or several, story-lines. This novel alternates between 1923 Kashgar and present-day London. The Kashgar sequences are riveting and extremely evocative of place and time. The London episodes are curiously uninvolving, perhaps because both the main characters in that time-line seem passive, drifting through their lives and pretty much unchanged at the end. The connection between the two story-lines is set up as a mystery, but really there is no great surprise at the outcome. I wanted to know more about both the present day protagonists, and wanted a greater sense of closure for the 1923 character. The Kashgar sequences kept me reading, but the novel as a whole felt like a lot of potential that is never quite fulfilled.