Alice Jones is concerned at the constant risks Casey takes as an engineer and persuades him to accept promotion to District Manager. When fifty people are stranded by a forest fire, the new engineer refuses to risk taking the Cannonball out to rescue them, leaving Casey faced with a difficult decision.
A fire eater is fired from the troupe he is working with. He does not take the news well and Casey needs to get involved in calming the situation.
A big spender, Arlo Bradford charters the Cannoball to pick up his new bride from a nearby town . He soon falls afoul of Casey with his flamboyant ways and easy spending. Casey's suspicions grow as a series of strange events dog the trip to the point Casey is convinced the man is a criminal
Casey volunteers to transport a cargo of nitroglycerine on board the Cannonball Express to rescue ten men trapped in a mining accident - but aboard the train is a man bent on a different mission in another race against time.
The Cannonball is forced onto a siding to allow a special silk train to pass that is attempting to run from the West coast to Chicago non stop. Unknown to Casey there are men on his train with a vested interest in seeing the train fail.
While Casey is away on a fishing trip, his friend Earl Bonner is put in charge of the Cannonball Express, during which time the train is robbed twice. Casey remains loyal to his friend and sets out to try and prove his innocence.
There is a shootout on Casey train and two men are dead. No one can figure out who the men where or why the shootout occurs. That is till Casey's son finds an intriguing clue
Bank robbers use Casey Jones and the Cannonball Express to escape after they rob a bank. Casey is forced to collaborate with the robbers because his family is on the train. Casey tries to stop them from escaping.
A passenger becomes ill and it is realized he has smallpox meaning all the passengers on the train are in danger. Casey needs to get life saving drugs but no town will let them stop.
Casey is accused of destroying a farmer's crop as a result of sparks from the speeding Cannonball Express. Although he is suspended during the investigation, Casey decides to take the Cannonball on a test run to find out about the truth of the claim.
Casey is commissioned by the Mexican government to carry a special shipment of Emperor Maximilian's crown jewels to St. Louis but the Secret Service agent guarding it on the Cannonball Express is an impostor planning to steal the treasure.
Casey stops at Jamestown to discover the local dispatcher has been arrested for murder. Complications arise when it is discovered the arresting marshal is the brother of the man who the dispatcher killed.
A mysterious girl boards the train and fools Casey into thinking she is a defenseless victim. Casey soon discovers the truth of the situation, and goes in search of woman after she has left the train.
Casey comes to the aide of immigrant railroad workers who are being threatened by the local cattleman fighting against the building of tracks across their land.
Johnny Ferguson has served his time. But his dreams of starting over are not going to be easy, especially if Luther Wagner has anything to do with it.
Acting under secret orders, Casey wrecks a train to fake the deaths of a Sheriff and 6 deputies. Unaware of the truth, the town folk of Midvale soon turn against their old friend.
It is Redrock's birthday and he discovers he is to be retired. He is at a complete loss as what to do and starts to make vague plans about starting a ranch to help keep him busy.
Casey and the Cannonball Express become unwilling participants in a plot to rob a Military escort of it's million-dollar payroll when outlaws disguise themselves as bank guards.
A track-walker saves the Cannonball from certain disaster, so Casey offers him a job, but he has a secret past . Russell Johnson plays the track-walker, 7 years before he and Alan Hale Jnr. would be stranded on Gilligan's Island.
A group of outlaws commandeer The Cannonball and prevent Casey and the crew from leaving town, the Sheriff is shot so Casey puts on the badge, but when he asks the townspeople for help only one steps forward. Lee Van Cleef is the bad guy.
A young girls one chance of surviving an attack of appendicitis while on the Cannonball, hinges on the Doctor aboard. The only problem with that is he is a being escorted by the sheriff as a prisoner on his way to jail.
After an old prospector is shot by an outlaw to steal his treasure map, Casey helps the sheriff catch the murderer, but then later discovers that the villain is the wayward son of carpenter Pete Dunlap, one of Casey's best friends.