A thousand years ago, while Europe sat in the early medieval period, China was building cosmic instruments to track the stars, water-driven mechanical clocks, and drilling rigs called heaven carts that bored deep underground for brine and natural gas. The film credits much of this to Su Song, whose astronomical clock towers anticipated devices the West would not match for centuries, and it tours geared milling machines and water-powered mass production plants that functioned like an early industrial base. Mining engineers get attention too: props designed to stop cave-ins and rudimentary gas-control devices built to handle the same volatile fumes that killed Egyptian and European miners. At a reconstructed iron furnace, historians explain how Chinese metalworkers cast a forty-ton iron artifact five hundred years before cast iron reached the West. Clay specialist Ye Hongming, who has spent decades studying the terracotta army, walks through what the buried soldiers reveal about the engineering behind them. The film also credits Chinese inventors with the world's first seismoscope.