This book is like a magnet with two poles. On the one side, we have the individualistic story of a girl discovering her duty to her ancestry. On the other side, we see a portrait of human progress and a commentary on mankind's effects on nature. In that individualistic story, she experiences a private climax when she attains some sort of mystic union with all the people of the past, but in the more meta-physical story, the commentary on modernity, the climax is death by murder.
Another way of saying those things would be to say that as Australian literature, the book symbolizes the duality of Australian history. Like all human history, the progress of man is often celebrated without properly remembering the injustices which occurred during progress. Jimmy's Aboriginal martyrdom makes for a great comparison to American history and the sins committed in the name of manifest destiny.
The symbolism of water is an uncanny reminder of duality in this novel as well. In Sadie's private life, we see her arriving at a sublime moment in the past. Having recently traveled to the past, she discovers an ancient ruin where a pool of water lays between enormous stones—an ancient altar of some kind. While contemplating, she discovers some religious truth about life and human nature, and that makes her an eligible witness for appreciating the evil of her own patriarchy.
