Through Felix, who is left alone with booze, audiotapes and a portable Olivetti typewriter, Angel’s story begins to emerge. Her real name is Gabrielle. And Felix isn’t likely to fall in love with her, since he is already in love with her mother. The book reaches back several generations on the maternal side of Gaby’s family to explain how Doris, her grandmother, defies her own mother and goes from their home in Woolloongabba to Brisbane on a couple of notorious days in 1942.

Those were the days when fighting between American soldiers and Australians, military men and civilians alike, erupted into what became known as the Battle of Brisbane. That event involved heavy injuries and pandemonium, and is likely to be better known to Australian readers than to others. Mr. Carey’s Doris is raped and horrifies her bigoted mother by bearing a half-American child.

The baby, Celine Baillieux, grows up to be beautiful, self-involved, actressy and politically pretentious. These qualities dazzled the 18-year-old Felix when he knew her as a college student in 1975 and felt like a hopeless inferior to Celine and her crowd. (“They all knew rhinoceros was a play,” Felix recalls.) And politics was everywhere in the air then. The book bitterly recalls Australia’s trusting attitude toward the United States, even after the Nixon administration made thoughts of an American-backed coup possible.

“We were naïve, of course,” Mr. Carey writes, via Felix. “We continued to think of the Americans as our friends and allies. We criticized them, of course. Why not? We loved them, didn’t we? We sang their songs. They had saved us from the Japanese. We sacrificed the lives of our beloved sons in Korea, then Vietnam. It never occurred to us that they would murder our democracy. So when it happened, in plain sight, we forgot about it right away.” This is a partial explanation of why “Amnesia” is the book’s title.

The novel also watches Celine develop as a pure narcissist when she becomes a mother. Gaby grows up in a political household where a computer is more Gaby-friendly than either of her parents. She becomes very adoring of an eccentric genius named Frederic, and he teaches her to write code, in which the book dabbles only cursorily. The use of hacking as either a plot element or illuminating ingredient is minor at best. When Felix writes that he “belly-flopped into the shallow end of computer crime” and stopped short of anything more complicated than Bitcoin, he’s speaking for the novel, too. Gaby is a brilliant hacker only in theory, and not in ways that make much difference to Mr. Carey’s overall scheme.