How wonderful it would be if everything could always be as clear and simple as it used to be when you were twelve years old, or twenty years old. If there really were only two colors in the world: black and white. But even the most honest and ingenuous cop, raised on the resounding ideal of the stars and stripes, has to understand sooner or later that there's more than just Darkness and Light out on the streets. There are understandings, concessions, agreements. Informers, traps, provocations. Sooner or later the time comes when you have to betray your own side, plant bags of heroin in pockets, and beat people on the kidneys—carefully, so there are no marks.