Twenty years ago, Rolf Langhammer embarked on a journey. It brought him to China in the early 20th century, a fragmented country ruled by warlords between tradition and cultural renewal. And eventually even to modern Shanghai. He was able to orient himself by using the many traces his grandfather had left behind during his years overseas: Letters from his family in Germany, a passenger list, and a visa. An attic find turned into detective work, and Rolf Langhammer became a genealogist.