During the 1970s-90s, under China's strict one-child policy, countless 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 Province, and 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, these girls would be forced to marry their sons.

Decades later, these women have grown up and are searching for answers. They want to know where they are from, and why they were traded like commodities.

With exclusive access, and from an award-winning production team, this is a moving investigation into the real human costs of China's longstanding one child policy.