It's good to be Emperor...but it's hard to come up with decrees...

The extraordinary story of China's 8,000 terracotta warriors begins two centuries before the birth of Christ. The First Emperor of China was preparing an extravagant tomb for his journey into the afterlife -- and decreed that he be protected forever by a monumental army...how was a terracotta army of this size made in less than two years using the technology of 2200 years ago? Secrets of the Dead's investigation shows that the Chinese may have Henry Ford beat by more than 2,000 years with their own assembly line...7pm

And at 8-m NOVA investigates the "Lost City of the Incas," the most famous archeological ruin in the Western Hemisphere. Why did the Incas build it on such an inaccessible site, clinging to the steep face of a mountain? Who lived among its stone buildings, farmed its emerald green terraces, and drank from its sophisticated aqueduct system? NOVA joins a new generation of archeologists as they probe areas of Machu Picchu that haven't been touched since the time of the Incas...