This week on Sinica, we take a break from the trial of Gu Kailai, the 18th Party Congress, and the recent flurry of disgruntled expat blog posts to cast our gaze back to the age of Mongol politics, barbarian cross-border raids, and that period in Chinese history which gave us the Great Wall as it currently stands in the mountains north of Beijing.With Kaiser Kuo abroad on business our show is a more intimate interview this week. Hosting is Jeremy Goldkorn of danwei.com renown, who is speaking with David Spindler, graduate of the Harvard Law School, alumni of the McKinsey consulting company, and now self-motivated and self-funded Great Wall scholar whose research over the past fifteen years has made him one of the foremost experts on the subject, not to mention more familiar with the countryside north of Beijing than anyone else we know.Need to feed your addition to Sinica? Have your computer download new episodes as they're released by subscribing through iTunes. This is as easy as selecting "Subscribe to Podcast" from the Advanced file menu and providing the URL http://popupchinese.com/feeds/custom/sinica when asked. As always, we also welcome people to download copies of our shows as standalone mp3 files.