Reporter Oliver Steeds and producer Matt Haan travel to China to follow one father's inspirational search for his son, who was abducted and sold into slavery. They expose one of the untold stories behind China's economic boom, discovering how thousands of young men with mental impairments have been kidnapped and forced to work in brick factories. The team meet 62-year-old farmer He Zhimin in Sanyuan town in central China. He Wen - his son who has the mental age of a child and used to live at home - went missing last June.