Noir is not a plot structure, though it often involves crime. It is a sensibility: the recognition that systems are rigged, that justice is contingent on who can afford it, that the line between the criminal and the lawful is less a moral boundary than an economic one. The protagonist of a noir novel knows this. The detective, the hired gun, the witness caught in the wrong story at the wrong time — all of them understand that the world is not organized in their favor, and they proceed anyway. What noir fiction offers at its best is not cynicism but a kind of hard-won clarity about how things work.
The canonical figures of the genre are Hammett, Chandler, and Thompson — James M. Cain for domestic noir, Patricia Highsmith for the psychological variant. Chandler's Philip Marlowe is still the genre's definitive protagonist: a man who operates in corrupt Los Angeles with more integrity than any institution around him, not because he expects this to make any difference, but because integrity is the only thing that cannot be taken from him. The prose in The Long Goodbye is as controlled as anything in American fiction; the plot is almost incidental to the voice.
The Stranger by Camus is not marketed as noir, but its structure is a crime novel's: a man kills someone, is tried and convicted, and faces execution. What makes Meursault a noir protagonist is his refusal of the system's terms — his inability to perform the grief, remorse, and social legibility that the court demands. The prosecutor is more outraged by Meursault's failure to cry at his mother's funeral than by the killing. Camus is describing something that all noir describes: the gap between the official account of morality and what morality actually is, and the violence done to those who expose that gap. Meursault is a noir protagonist stripped of plot — all the noir sensibility with none of the genre conventions.
Blood Meridian by McCarthy is historical noir pushed to apocalyptic scale. The Kid is a noir protagonist in the classic mode — an outsider moving through a landscape of organized violence, unable to affect its outcome. The Judge is the noir system made flesh: a figure of absolute authority who operates outside any law, answerable to nothing, convinced that his violence is the world's fundamental truth rather than its perversion. McCarthy's West is noir's setting pushed back to its origins — the period when the American mythology of freedom and the American reality of violence were still openly coextensive.
The Journalist and the Murderer by Janet Malcolm extends the genre into nonfiction in a way that is illuminating about noir's essential character. Malcolm's subject — the asymmetric relationship between a journalist and a source, in which the source trusts and the journalist uses — is a noir relationship. The journalist is a detective of sorts, and the source is the person who doesn't understand the rules of the game they've entered. Malcolm's argument is that this dynamic is not aberrational but structural: that journalism, like noir fiction, operates in the territory between official ethics and actual practice. The book is short and should be read carefully, because the argument is more uncomfortable than it first appears.
The deepest quality of the noir tradition is its honesty about power. It takes as given that institutions serve their own interests, that justice is expensive and unevenly available, that the people who make the rules are largely exempt from them. These are not radical claims; they are the experience of most people most of the time. Noir fiction has always been popular because it is honest about this in ways that other genres aren't. What distinguishes great noir from competent noir is whether the honesty produces insight or just attitude. The books above produce insight.