You have to suspend a lot of disbelief for this tale of anthropologists, scientists and life-prolonging turtle meat, but it is worth it. This is a story of personal and cultural destruction, of how the road to hell is paved with good intentions and how ambition can have some totally unforeseen consequences. There is also a question of whether the narrator, in describing the rituals of the Ivi-ivuans, is reliable or fantasising.
When he came down, he was slower, and clutching something in his hand. He leapt down the last five feet or so and came over to me, uncurling his fingers. In his palm was something trembling and silky and the bright, delicious pale gold of apples; in the gloom of the jungle it looked like light itself. Uva nudged the thing with a finger and it turned over, and I could see it was a monkey of some sort, though no monkey I had ever seen before; it was only a few inches larger than one of the mice that I had been tasked with killing, and its face was a wrinkled black heart, its features pinched together but its eyes large and as blankly blue as a blind kitten's.