The authors, who are among the top experts on the Tarim mummies, do a very good job of detailing the scholarly process of determining who these people were and their wider linguistic and religious contexts. The book presents information on the mummies themselves, and their 'racial' affiliations. Both Caucasian and Asian mummies were found in different parts of modern Xinjiang, though Caucasian ones predominate for the most part. The questions are: who were these Caucasians mummified in ancient times, how did they get to what's know China, what language(s) did they speak, and what historical roles might they have played? It turns out these are complicated questions, and associating these mummies in a linguistic group and that linguistic group with an archaeological culture proves to be a difficult task. The authors, however, have done a most convincing and nuanced job answering these questions. It seems that several languages were used concurrently-- Chinese for imperial administration, Prakrit for religion (specifically Buddhism), Sogdian for trade, and Saka and 2-3 Tocharian languages for everyday speech. Connecting these Tocharians to India's Kushan dynasty isn't so clear cut-- it may be that Iranian-speaking Saka who also lived in the region were actually the Yuezhi of Chinese records who became the founding members of that influential dynasty. Anyone interested in the spread of Indo-European language and culture, in the Silk Road, in the spread of Buddhism, in Chinese imperial history, or in mummies in general would do well to read this book. The authors conclude the book with a brief overview of several East-West exchanges, noting both Chinese contributions to the West such as the compass and, later on, moldboard plows, and Western contributions to China, including the Chariot and wheel, probably brought in by the early Tocharian speakers, and Buddhism, which spread from Indian to Central Asia (or 'Inner Eurasia' as the authors write) and through the Tarim Basin along the Silk Road into China. This to me is an exceptionally interesting topic, very ably covered by the authors.