A nun is found murdered on the steps of the Quality Couch, Sydney's most expensive house of ill repute. She was Sister Mary Magdalene, an idealistic young woman who previously had worked at a mission in Nicaragua. Detective Inspector Scobie Malone, that most human of cops, picks up the trail when he discovers that her real name was Teresa Hourigan -- the illegitimate granddaughter of Fingal Hourigan, one of Australia's most powerful businessmen, who is currently entertaining some rich contras at his palatial home.

As Detective Malone uncovers more and more political involvement by the Church and more and more crime in Australian big business, it becomes clear that this is a case of corruption spanning continents and decades.