Great background info for the story here, or just for general interest's sake! Silk Road Seattle is "an ongoing public education project using the "Silk Road" theme to explore cultural interaction across Eurasia from the beginning of the Common Era (A. D.) to the Seventeenth Century."

Their website contains lots of really interesting stuff, including sections on Art of the Silk Road, Cities and Architecture along the Silk Road, and Silk Road maps and geography. Best of all is a rivetting collection of primary historical sources: Silk Road Narratives: A Collection of Historical Texts.