Between the 1970s and the 1990s, under China's strict one-child policy, an unknown number of baby girls were abandoned by their parents who wanted to have a son. Tens of thousands of these unwanted girls were brought to Putien, Fujian, where they were raised by foster families. But their foster parents didn't do this out of the kindness of their hearts. Instead, they had a clear goal: one day the girls were to marry their sons. Decades later, the women have grown up, and they want answers: where did they came from? And why were they traded like a commodity?