Writer Will Millard visits the treehouse-dwelling Korowai tribe in Papua, Indonesia, to try and understand the pressures they face as they move into the modern world. Will returns for his second trip to the Korowai to spend more time with Haup (White Beard) and Halap. They are some of the last remaining Korowai still living permanently in a treehouse, without any real contact with the outside world. When Will first meets them, their adopted son August is there with them in the forest and his wife Amel gives birth one night, cutting her own umbilical cord with a sharpened piece of wood. But it soon turns out that they spend most of their time in the government-sponsored villages six hours walk away, and have decided to come to the treehouse to see if they can work with the film crew. So Will asks them to return to their government-built village, preparing to spend 10 days living with Haup and Halap alone in the middle of the forest.
Will returns for his third trip to Korowai, to try and find August and his family, but relations break down and he finds himself in the middle of a very dangerous situation.