Oscar-winning director James Marsh (Man on Wire) shifts his focus from man to monkey to tell the remarkable story of Nim, a chimpanzee who managed the unique feat of learning sign language after being raised like a typical human child. Interviews with Nim's trainers as well as other key researchers are combined with archival footage to offer incredible insight into the experiment that would forever alter our perceptions regarding the differences between man and beast. By attempting to turn Nim human, scientists learned more about the true nature of humanity than they ever thought possible.