Koko, a six-year-old gorilla, is the subject of a controversial Stanford University research project conducted by Penny Patterson. A perceptive simian who communicates with humans via sign language, Koko knows more than 300 signs and can combine them to make new hybrid descriptions. Director Schroeder and cinematographer Almendros present a visual argument exposing the contradictions that arise when scientific experiments are used to graph human behavior onto animals.