The central area of New Guinea was thought to be uninhabited until aerial photographs showed signs of human habitation. David accompanies an expedition into the interior to find and make contact with these people and map the area. He encounters tree kangaroos, an echidna, goura pigeons (another fabulously beautiful bird), an emerald tree python and leeches along the way. When they find a house, they don't hesitate to break in and rifle through the contents. When they eventually find people, they try to get them interested in trading beads and salt for food. They have limited success but then the people disappear - possibly (David feels) pushed too far too fast.