'Angel of Light,'' is a political novel, though one less interested in the practice of politics itself than in its power to evoke certain deep human impulses toward violence. The story is very generally based on the fall of the House of Atreus; once again a brother and sister seek to avenge the killing of their father by murdering their mother and her lover. But here the myth is updated, and altered, by the terms in which power is now exercised in America - the shadowy intersections of government, business, finance, ideology and organized crime.... I'm much impressed by Miss Oates's ability to enter and explore the personal sources of the high-minded violence that's now such a familiar fact of public life. I'm impressed too by how clearly she remembers that her first duty is not to judge but to understand.