In 1984, 4000 buried terracotta warriors were discovered in Jiangsu Province, China. They were an army – infantry, archers, charioteers and horses. But they were disorderly warriors. They'd been interred carelessly, and in great haste. Archaeologists Wang Kai and Qiu Yongsheng suspected they were the guardians of the tomb of a long-ago king. But which king? Where was his tomb? ...