A shipwreck off the Cape, a Portuguese treasure buried three hundred years ago in a ruined fortress on the Zambesi, and a girl travelling with her father, who wants the gold. Haggard went to South Africa at nineteen and helped raise the Union Jack over the Transvaal; the wreck of the Zanzibar at the start is taken from a real disaster he had read about, and it is the best-written passage in the book.