A grand jury witness against a mobster charged with murder is killed in broad daylight at the Madrid County courthouse, leaving Sheriff Sam Cade and one of his deputies as the only two witnesses left. What Cade doesn't know is that the hit man is an old friend and former resident of the county who has come back for a visit.
Sheriff Cade searches for a bail-jumper in a tightly-knit mining town in the county's outskirts. He runs into a wall of silence about the man from residents fearful of the town boss, and unwilling to risk the loss of the mine despite its hazardous working conditions.
A ranch hand is found stabbed to death after a barroom brawl, and the main suspect is the young Mexican co-worker he had been harassing. But Cade soon finds that the murder involves something much bigger going on at the ranch, including the use of illegal aliens and heroin smuggling.
A young man is scheduled to be executed in a few days for the murder of his girlfriend eight years earlier, and Sheriff Cade, who has always believed in his innocence, tries to find some evidence to get a stay. The first break is the discovery that the murdered girl was taken to see an abortionist, but then the abortionist is himself murdered.
Cade searches for two escaped prisoners, one of them John Grey Wolf, a ruthless killer who once served as Cade's deputy. A young Indian tracker is asked to assist Cade in the search, even though he admits to being sympathetic to Grey Wolf.
Everybody loves Jack Pilgrim, a model citizen of Madrid City. The trouble is that, Sam Cade gradually finds out, this angel is in fact a fiend. Nobody else is aware that this good man is a mole on the payroll of an enemy country who has been assigned a sabotage mission which could have dreadful consequences.
While attending a convention in Los Angeles, J.J. recognizes one of two fugitive brothers whom he had dealt with earlier in Madrid. After alerting Cade, he is then taken hostage by the brothers, who are planning another major heist. Cade works with an L.A. lieutenant to find J.J. and stop the gang.
Sheriff Sam Cade and his deputies track down a convict out on parole who has delusions that he is Billy the Kid. He acts out his fantasy by committing the same types of crimes that the famed outlaw did. He also kidnapped his young son placing him in grave danger.
Madrid County's beauty queen is found murdered, and the main suspect is a rodeo rider who had been seeing her. But Cade has doubts about the reliability of the main witness against him, and he learns that a powerful Congressman was also involved with the victim.
The foreman of a major rancher is killed, and his boss insists that the killer is the young Middle Eastern oil heir who's been dating his daughter. But Cade believes the answer lies elsewhere, as he learns the murdered man was involved in selling drugs to local college students.
J.J. is shot and seriously wounded after he stops a motorist and discovers that he is transporting a shipment of gold. Cade goes undercover as the insurance investigator who found both men, hoping to find out who's running the operation by convincing underlings that the wounded motorist J.J. shot talked before he died.
Two derelicts are chased after witnessing a major industrialist being transported after suffering a stroke. One of the derelicts is later found dead, and the businessman's associates are determined to silence the other one, fearing that knowledge of their boss's condition could lead to the loss of a loan which is needed to save his company.
Cade and his deputies know that something is being planned, though their only clues are a stolen barricade, a toy pistol, a syringe, pieces of muzzling, and the theft of a station wagon. But soon it also involves a murder. And whatever it is, Arlo's brother is masterminding it.
A local businessman and the mayor's daughter are found dead after the truck they were in goes over a cliff. The man died from the accident, but the girl was strangled with a bead necklace. A young Indian known to possess such a necklace is arrested, but the arrest inflames the local campus and the Indian community.
Even though Willie Ball has confessed and been sentenced for the murders, Cade does not believe him, feeling that he only confessed to draw attention to the cause of Indian rights. Meanwhile a Chicago cop has orders to extradite Willie for six similar killings that occurred there, and Cade has to keep persuading him to hold off while he checks out all leads.
Cade and his deputies investigate a burglary at the home of a rancher, but nothing is missing and no one seems to know what the burglar was after. Then the rancher is murdered, and his wife, an old flame of Cade's, is the prime suspect.
An old Indian witnesses a ruthless trapper killing a man, but refuses to identify the killer, fearing it will only lead to more violence. He still maintains this belief even after the trapper tries to kill him.