Over a century ago, the first explorers in the Congo forests sent back terrifying accounts of an aggressive ape, "half man, half beast," which inspired the myth of King Kong. Ever since then, we have had little contact with these lowland gorillas - they have remained a mystery to us. We have come to know the mountain gorillas of Rwanda intimately, but what are King Kong's wild lowland cousins really like? GORILLAS: ON THE TRAIL OF KING KONG follows Sir David Attenborough and intrepid cameraman Gavin Thurston on the trail deep into the heart of three gorilla sanctuaries in northern Congo: Ndoki, Odzala and Lossi, in search of the true nature of the lowland gorilla.