The first of a three-part documentary investigating the brutal murder of world-renowned mountain gorilla expert Dian Fossey.

Dian – whose work was dramatised in 1988 film Gorillas in the Mist – set up the Karisoke Research Centre in a remote region of Rwanda in 1967 and began the first long-term study of these amazing and endangered creatures.

She lived and breathed for her work and saw the gorillas as her family, protecting them from poachers however she could. But on 27 December 1985 Dian was found murdered in her cabin.

Her research assistant Wayne McGuire was charged with her killing, but many questions remain about who actually killed her and why.