Harry Baird lives in Calliope Bay, five houses and a shack, and the ruins of the old meat works. As Harry and his young mates play in the cave, on the wharf and in the works, scar faced old man Sam Phelps looks on, impassive, opinion unknown except perhaps to his perennial companion Sydney Bridge Upside Down, the horse. Harry's mother has gone to the city for an undetermined period, and Harry's beautiful older cousin Catherine arrives in the bay. Harry is young and confused and sees Catherine as part sister, part replacement mother, part object of sexual awakening.
Ballantyne throws an array of themes at the reader - the terror of the killing rooms of the defunct works, the joy of boyhood, the ubiquity of domestic violence. While the children are unrestrained, enjoying fresh air, adventure, fun - the adults are mostly overwhelmed by isolation, which promulgates the tiny settlement like salt soaks the air.
Through this the plot is mysterious, and sudden. With the scarred hairy and shady characters, this is a twentieth century country Dickens. Events are not clearly explained.
Although it is now considered a New Zealand classic, if you did not know it was a New Zealand writer, it is not clear that it is even set in New Zealand - all of the place names are invented (I think) and there is not a single Maori word. Interesting.