Smith convinces a blinded bank robber to lead him to the location where the bandit hid his loot in exchange for arranging for an operation to restore his sight. Two of the thief's former confederates decide to help themselves to the plunder.
Ma Gates and her brood come to Denver to avenge themselves upon Whispering Smith for killing her husband and their father when Smith tried to arrest the gunman 10 years earlier.
Jeff Whalen murders his brother, upon learning that Frank has become engaged to his former girlfriend. After stealing the money Frank earned from the sale of his crops, Jeff frames a neighbor, but Whispering Smith believes the evidence against the accused murder is too pat and searches for the real culprit.
Members of an outlaw gang that George Romack formerly rode with try to blackmail the Denver police detective into assisting them pull a robbery. When Romack refuses to resume his criminal career, the gang abducts his wife to force his cooperation
Smith and Romack go undercover for the Army to investigate the deaths of three young officers all of who were shot in the head during Indian attacks. The detectives are faced with a number of suspects - an ex-Confederate officer with a grudge, a sergeant who hates officers and a private jealous of anyone who romances the commanding officer's pretty young daughter.
A young man who just announced his engagement is accused of murdering a gold-digging woman and refuses to participate in his own defense. Smith and Romack investigate and discover the trail of evidence leads to a surprising culprit.
After receiving a note threatening his life, Ralph Miller requests protection from the Denver police department. Smith and Romack are assigned as bodyguards but the two detectives fail to prevent stock promoter from sipping a poisoned drink, which was fortunately not lethal. Smith tries to dig into the man's past to learn who might have a reason to threaten Miller's life.
A young woman arrives in Denver searching for her mother, a former Mississippi riverboat entertainer, who has sent her to live with a cousin fifteen years earlier. Smith and Romack take an interest in her plight when thugs try to force her to leave town despite her apparent lack of progress.
The Denver police force discovers two hours too late that they've released a murderous bank robber into the hands of his confederates rather than Phoenix deputies as they thought. Smith and Romack set out in pursuit and follow the trail of bodies to Leadville, Colorado where they hope to grab the remaining gang members and their ill-gotten loot.
A gambler on a long losing streak tries to recoup by betting that Whispering Smith will not live another 48 hours. Rival gamblers hire gunmen to kill or protect Smith. The Denver detective is none too happy about all the unwanted attention.
Smith captures a jail-breaking outlaw near the Wyoming border and asks a small town sheriff to board the criminal overnight. Smith plans to set off with his prisoner for Denver in the morning, but the local lawman has other plans for his temporary prisoner and the silver bullion that the crook has stashed nearby.
Smith suspects an influential businessman of murdering his brother when he announces he has an iron-clad alibi without being asked. Over the objections of Police Chief Richards, Smith focuses his investigation on proving that the grieving relative was not in bed in Leadville at the time of the murder in Denver.
Smitty becomes suspicious when the alleged mugger a woman claims to have shot is found to wearing a distinctive ring but didn't have a mark on his finger showing he wore it for any length of time. His suspicions only grow when he discovers that the dead man is carrying papers identifying him as a wanted criminal with a price on his head and his killer promptly claims the bounty.
While pursuing an outlaw gang, Smith rides up to an abandoned house, hears a shot and sees a body come crashing through a second story window. Police Chief Richards is incredulous when Smith returns with a story of the body disappearing when he searched the house, but the Denver detective doggedly pursues the scant clues towards proving a romantic triangle led to the murder.
Three men are found murdered on consecutive nights with the killer following the same modus operandi - the victims were all shot between the eyes and the third button on their vest was removed. The Denver detectives must determine what connection the men had with each other and Smith discovers information that links the crimes to the beautiful proprietress of a popular local casino.
Hap Ward is on his way to pay off a bank loan on his store. He is called off a stage, his money belt is taken, and he is shot. Jodie Tyler shows up with a bag full of money and an interest in the store. Smitty is on the trail of the killer.
An English lord who is also a noted poet is hired to recite his poetry at the Denver Opera House as a benefit for the widows and orphans of miners killed in a recent mine disaster. The benefit nearly doesn't come off when the stagecoach rolls into town without its driver and its famous passenger. Smith and Romack backtrack along the stagecoach's route to try to learn what happened to Denver's distinguished visitor.
An alcoholic lawyer who threatened the owner of a casino the night before is framed for his foe's murder. The barrister refuses to participate in his own defense, believing his death would be a blessing for all concerned, but Smith's investigation points to other culprits interested in the dead man's gambling receipts.
A match race between two feuding family's prize horses ends in tragedy when one of the jockeys is shot from the saddle by an unknown assailant. Whispering Smith declares the race a draw but the two parties insist on running the race again, betting their ranches on the result. While George searches the crowd for a potential killer, Smith enters his horse in the event to keep the race honest.
When a mining engineer is found stabbed in the back outside his partner's saloon, Smith and Romack strongly suspect a falling out between friends was responsible for the man's death. Their investigation founders when none of the saloon owners employees will talk to their police until a Swedish dishwasher discovers that the saloonkeeper is two-timing the bars beautiful chanteuse.
Smith and Romack investigate a series of bombings that rock Denver. The detectives can find no apparent connection between the two victims, one a mine owner, the other an Irish traveling salesman, until they discover a ball of twine in a popular boarding house that was linked to both crimes.
Enrico Spanato, a Sicilian interpreter is accused of killing a fellow Italian by several of the dead man's friends. Although Smith finds evidence that someone might have fired a shot at the interpreter, he can find no one who who will testify that the shooting was self-defense because the Italians in the neighborhood fear the growing power of the Mafia.
Whispering Smith captures Sam Chandler, a fugitive near the Mexican border. His plans to return him to Denver where he is wanted for murder are dashed when the two men are captured by Mexican bandits who only keep them alive to serve as personal slaves.
Smith and Romack have their hands full investigating a violent death that might be murder and dealing with a gang of ex-convicts who have suddenly descended on Denver. The former wards of the state appear to be planning to settle an old score, but who is the would-be victim? And is the gathering related to the late night shooting that Bob Mullet claims was self-defense?
Two outlaws steal a valuable jeweled statue from a Catholic church, but the parish priest refuses to give Smith a description of the villains unless he agrees to pursue them unarmed. The Denver detective reluctantly agrees and manages to catches up with the culprits in the desert. Smith begins a deadly game of cat-and-mouse in the middle of the waterless wasteland using canteens of water as deadly weapons.
A not-so-devoted husband hires a Kansas City killer to travel to Denver to murder his wife when the couple arrive by stagecoach several days later. After the young woman dies, he sets about arranging for his mother's return to England after an absence of 14 years. The older woman, however, becomes suspicious of her doting "son's" true identity.