Colleen McCullough's 1977 novel, The Thorn Birds, became an international publishing sensation as its sales climbed past the seven-million mark. This saga of three generations in an Irish Catholic family in Australia seemed to pique interest in the history and culture of the continent, as witnessed by a spate of books and films set "Down Under" that entered into the annals of pop culture in the years following The Thorn Birds's success. Yet McCullough has enjoyed only intermittent critical approval for her fiction throughout her career, and was never able to match the tremendous success of the 900-plus-page blockbuster. Her books often clock in at several hundred pages, and in interviews, McCullough comes across as equally loquacious in person. "I think there are two kinds of writers: those who write because they can't talk and those who write because they talk so much nobody listens to them," she...