Imagine a world without wild elephants. For some in the frontline of animal preservation it’s not a difficult image to conjure. In Africa, one veteran wildlife campaigner believes it could be a reality within the next 20 years. The reason? A rampant, illegal trade feeding China’s voracious appetite for ivory. The Asian giant’s burgeoning middle class can’t get enough of the stuff so Africa’s elephants are being hunted and slaughtered like never before. Foreign Correspondent goes undercover to expose this shameful, devastating trade.