Two outlaws rob a stage, kill the driver and leave the shotgun guard for dead. The guard survives the attack and, with the help of a passerby, manages to make it to Diablo. The man can't defend himself from charges of robbery and murder because the bullet wound has caused complete amnesia. Annie and Lofty set out to prove the man's innocence.

A gang of hired killers rides into Diablo. Lofty believes that they're in town to murder a state senator with powerful enemies in the capitol. When Lofty discovers that the gang's leader once rescued him from certain death during their days in the U.S. Cavalry, he is reluctant to take him on and possibly kill him in a shoot-out. As a result, the townspeople force Lofty to resign.

A tenderfoot from Mississippi travels to Diablo to visit his sister and loses his watch in a stagecoach robbery. The headstrong youth is soon telling everyone how to do their jobs - including questioning Lofty's search for the outlaws who robbed him and his sister's experienced ranch foreman about his business methods. The young man really bites off more than he can chew when he discovers the identity of the thieves and tries to bring in the entire outlaw gang single-handed.

During a heated election campaign between honest lawyer Dave Morgan and Carter Holmes, a crooked politician, the contest takes a violent turn when Holmes tries to have his competitor murdered. When his henchmen fail, Holmes hires a notorious gunfighter to take care of the job, but is surprised when the gunman promises to get Holmes to back out of the election without violence.

While rummaging through an old trunk, Tagg and his friend Johnny Ward, the son of a murdered lawman, find evidence that they believe proves his uncle is an ex-convict and may be part of the outlaw gang who recently robbed Diablo's bank.

When their handicrafts meant to trade for goods at the local trading post are stolen by white men, the Navajo tribe decides to seek vengeance by going on the warpath. Since whites are forbidden to enter the reservation, even to seek peace, Annie must dress as an Indian maiden to prevent bloodshed.

Annie, Lofty and Tagg try to help a young Indian when he inherits a stagecoach line with a valuable mail contract after his white patron, the owner of company is bushwhacked and murdered. A rival businessman who craves the contract tries to frame the young brave so he can take over the valuable concession.

After years of fruitless prospecting, old Scissorbill Childers finally strikes it rich and decides to use his new-found wealth to open a bank to grubstake other prospectors who are searching for gold and silver. New found wealth always attracts criminals so Lofty has his hands full trying to thwart claim-jumpers and swindlers. To make matters worse, the government assayer determines that Childers' gold ore comes from the same claim as that of a murdered prospector.

While Annie and Lofty pursue an outlaw who killed a sheriff, Tagg tries to coach his schoolteacher on the finer points of romance.