The giant hydroelectric dam in the Three Gorges of the Yangtze River has been controversial since construction began in the early 1990s; but now, as it nears completion some two decades later, a warm winter and a diminished Himalayan snowpack have cut the Great River's volume by half, bringing all the critics worst fears to realization. German hydrologist Hans Fruehauf is sent to China to assess problems at the dam for one of the project's big investors. Hans decides to travel the length of the Yangtze to view and analyze the altered watershed. Yet what begins as an engineering study of the serpent-like river rapily becomes a dangerous voyage into the Asian underworld and a dark forbidden romance.