The four Rangers are after Midas Mantee who wants revenge for being crippled and sent to prison. Erik is trying to work undercover but Reese continually fouls up Erik's plans as Mantee robs several banks with crafty planning.
Chief Tohpay plans to take back the lands for his people by driving the Army and settlers out. He has the help of John Garth who is training Tphpay's braves to use Army techniques and weapons with great success.
Jake Murdock wants Parmalee dead so he hires Dr. Duvain to use a mind control drug on Reese to have Reese kill Parmalee. However, others accidentally trigger Reese's response to the drug making them think Reesee has gone crazy.
The four Rangers allow a Mexican rebel under US protection to be kidnapped and taken to Mexico for execution. Parmalee forces them to go to Mexico and rescue him. Getting him out of prison requires going "undercover".
Reese's enlistment in the Rangers is up. He decides to use reward money to buy Texas land and leave the Rangers. The land is covered by water filled with deadly alkali. The Rangers decide to help Reese recover his money.
Based on a clue from a citizen, Parmalee sends Reese and Chad to Dry Wells to investigate. They find a new sheriff and a changed town with several known outlaws from Oklahoma. Erik and Joe go undercover while Reese is killed.
A circus seems to be at every town where banks are robbed via mysterious means. Erik decides to go undercover as a magician with the circus. The other rangers are sent to help but the robberies continue unabated and no money is found.
A payroll is to be delivered with only one way to the mine which the Sweet family is watching. Erik scouts for a second pass but is captured by the Sweet family. The rangers decide to use a sick wagon but it is carrying more than money.
Reese's voice is identical to a wealthy gambler. When the Rangers learn he may be kidnapped they decide to use Reese in his place to protect him and catch the kidnappers. The plan nearly fails when the kidnappers learn who Reese really is.
Nine year old Gussie Smith hires three Rangers who are broke to take her from Laredo to San Remo. Joe is worried as he believes Indian Pete tried to kill Gussie when they were on the stage. They find he has reason to worry about her.
Select people are disappearing while others are being left dead. The Rangers learn a man is trying to recreate a Roman empire as Hannibal Rex. Joe and Reese become slaves while Erik and Chad impersonate an architect and sculptor.
Prince Lazlo came to Laredo to sign a treaty. After multiple attempts on his life, Parmalee decides to have Chad take his place as they look like identical twins. The Prince loves western life while Chad embraces the Prince's bride to be.
The Rangers are called to rescue a wagon train trapped in a valley by Indians. Parmalee decides the only option is to bargain with the Chief. Joe and Reese negotiate at their camp where the Chief's robust daughter wants a husband - Reese.
The Rangers are after the Dixie Gang - two of them. Reese is told to solve small time robberies in Laredo - committed by Matt Dixie and friends while the other Rangers are after the Sam Dixie gang which is holding up several banks.
When a convict turned minister is run out of town by Clay Morgan and his gang, he turns to Parmalee for help. Parmalee decides to send Chad and Erik to the town posing as ministers to uncover the truth and take down the gang.
The Rangers are after Johnny Rhodes plus they must help with a gold shipment from Mexico. After a dust up with Johnny Rhodes, Reese has amnesia and is mistaken for Rhodes. Chad and Joe are tracking Rhodes finding Reese playing Rhodes.
Parmalee sends Chad, Joe, and Erik after the AWOL Reese and the Gully gang who is terrorizing the Comanches and civilians. A Comanche boy orphaned by the Gullys, wounds Reese but Reese comes to adore the boy only to run into Gully's gang.
Joe rescues Jem Sing who is being taken to Mexico to marry Gen. Shen Ti the head of a major opium business. Ti is wanted in the US so when he kidnaps Jem Sing and Joe, Parmalee decides Chad and Erik need some vacation time in Mexico.
Reese, Chad, and Joe are sent to Grover's Bend to protect a group that believes in non-violence and are sheep herders in cattle country. Reese with a bad back falls under the influence of the beautiful pacifist Della Snilly.
Bart Cutler is reported in the area at the same time Jessica Boyd is in Laredo visiting her brother-in-law, Ed Parmalee. Problem is that Bart Cutler is really Frank Parmalee, Ed's dead Civil War hero brother putting the Rangers in a bind.
A man meeting the Rangers loses money to them in poker where Cotton is the big winner. The next day he asks to ride with them to Laredo. He is killed on the way to Laredo and asks Cotton to deliver his case and a message to his niece.
On the return to Laredo Reese seeks refuse from a storm by stopping in Small Chance only to find a ghost town. The one woman he finds says the shaking town has ghosts but Reese soon learns it has real threats to others and himself.
When an Apache is seen over the dead body of a woman who befriended him, everyone assumes he is guilty. He refuses to speak for himself but the Rangers question his guilt. As part of the jury Joe is only one to question his guilt.
Parmalee sends each of the four Rangers one by one to evict a family from their home. A railroad has bought the property but the Rangers are distracted by the freewheeling family plus they learn there may be an unforeseen complication.
The rangers must deliver a load of newly developed nitroglycerin to the army while outwitting a quick change artist trying to steal it. Hoever, the danger and attempts on their lives have them questioning if it is worth the $50 bonus.
After a judge and hangman are killed on their way to the reading of a will of Jake Ringo who was hung, Parmalee receives a similar invitation. He takes Chad and Erik along hoping to recover the money Ringo stole and arrest the others.