The Ox-Bow Incident begins as a Western horse-opera with all the stage settings and characters of a cowboy thriller, but it ends as a saga of human misery. The novel has the action and pace of a classic drama. The mob assumes the nature of a Greek chorus, now on one side, now on the other. The story rises toward an inevitable climax and, as it does so, forcibly states the harsh truth: The law of survival is linked to the curse of relentless cruelty. Walter Van Tilburg Clark made the Western thriller a novel of art.

Although set against a Nevada landscape in 1885, the novel’s portrayal of mob justice is timeless. The tragedy in the novel involves not only the theme of innocent people wrongly punished but also the theme that unjust and cruel acts can be carried out by intelligent, moral persons who allow their sense of social duty to corrupt their sense of justice.

Bridger’s Wells, Nevada, the initial setting for the novel’s development, offered its citizens recreational diversions limited to eating, sleeping, drinking, playing cards, and fighting. Into that frontier setting stepped Gil Carter and Croft, who learn that rustlers had provided the place with an exciting alternative, lynching. Osgood, the Baptist minister from the only “working church” in town, realized early on that hot mob temper could subdue individual reason and sense of justice. In times of despair, reason and justice seem less attractive than immediate action. Bartlett, a rancher who found rustling a particularly vile threat, argued that “justice” often proved ineffective and worked too slowly to guarantee that guilty men would pay the penalties for their crimes. He was able to persuade twenty townspeople to form an illegal posse, even though none of the men he exhorted owned any cattle and only a few of them even knew the allegedly murdered man. One man, physically weak and unsound, won over the rest by deriding those among his listeners who opposed his argument. Notwithstanding their thoughtfulness, the words of reason spoken by the storekeeper Davies proved unsuccessful, especially against the renewed harangues of the self-important Major Tetley.

Major Tetley’s son Gerald, whom his father forced to take part in the posse, painfully realized the weakness of individuals who were afraid to challenge the mob and felt that to resist would be to admit weakness. “How many of us do you think are really here because there have been cattle stolen, or because Kinkaid was shot?” he asked. In the absence of Sheriff Risley, who as the legally constituted police authority might have stopped the lynching, the formation of the illegal posse, the manhunt, and the lynchings all proceed with the inevitability of a Shakespearean tragedy.

In the eleventh hour, no gesture suggesting innocence could spare the doomed men. When Davies, in an effort to save the life of a man he believed was innocent, wanted to communicate Martin’s emotional letter to his wife to the posse, Martin himself objected. He used the incident to make another point, that even an initial promise to preserve the integrity of his letter would have proved futile among men in whom conscience had failed as a measure of just conduct. In a moment where bravery might understandably have failed among men about to be hanged, the Mexican removed a bullet from his own leg, washed the wound and dressed it with a fire-heated knife. He tossed the knife into the ground within an inch of where its owner’s foot would have been had he not, in fear, drawn quickly away. The Mexican, who smiled often at the...