Archie casts a pall on the family's Yuletide spirit when he complains that he was passed over for this year's Christmas bonus.
After performing in Vegas on Christmas Eve, the Partridges start the drive home. The bus breaks down in a town with one inhabitant. Disappointed about being away from home for Christmas, the prospector tells them a Christmas story.
Bill reports Graeme and Tim to the Women's Liberation Front after he disapproves of their treatment of Graeme's new totty. As a punishment, they are sent to work for Lord Charles (a male chauvinist) - Graeme as the butler and Tim as the maid.
Oscar chooses between a poker game and a birthday party for Felix's daughter.
When Brett's plan to capture a traitorous British spy by pretending to be him results in his own capture, Danny enlists the aid of one of Brett's relatives to rescue him.
Ed discovers that a man sought on assault charges is Bernie Simmonds, a man who was in his class at school. Whilst pursuing the investigation he meets again with Ann Garfield, his first love; now widowed with two small children. Love, it seems, is set to blossom twice; unless Ann knows more about Bernie than she is letting on.
Hannibal Heyes and Kid Curry, two of the most wanted outlaws in the history of the West, are popular "with everyone except the railroads and the banks".
Desperate to stay alive for the sake of his nine-year-old grandson, an elderly, near-penniless Jew on the brink of death pins his hopes for salvation on the coming of the Messiah. A mirror reflecting an alien landscape figures into an antique dealer's scheme to rid himself of a hateful business partner.
Endora transforms Darrin into a gambler. Samantha inisists Endora remove the spell. Endora makes more trouble by having Darrin bet on a horse named Fancy Dancer that is bound to lose, and Darrin gets Larry and a client to place all bets on Fancy Dancer. Samantha pops to the stables to talk to Dancer about winning the race for her husband and his friends. In the race, it seems like Dancer is bound to come in last, but he pulls through and wins!
A woman shoots her overbearing brother, claiming she thought he was a burglar. Columbo doesn't buy the self-defense claim - he know's it's murder.
The Trio help a young deaf-mute save a guard from a warehouse fire. Linc then gets involved with helping the young-deaf mute who is targeted for assassination.
Lucy Carter, a widow with two teen children, takes a job as a secretary for her stuffy brother-in-law.
The conclusion to this three parter. Dillon kills the guard that was gunning for him and the passengers take the train back over. The only problem, all the fuel has been destroyed so they have to get more fast. Festus and Newly are still out with the gold leading the men from the train on foot. Dillon's legs are numb and Doc has no choice but to operate whether he cripples him or not. Leaving the gold shipment and taking the mules, Newly and Festus head back to the train to try to get it going. Sinclair has the men push the wagon back to the train and gets there in time to keep it from taking off. Beth tells Sinclair about Matt Dillon, but Dillon's faster than a gun even lying down and ends up killing him. The train takes off leaving the bad guys and all their gold sitting at the tracks with no way to get anywhere.
When Luke Calhoun loses all his money in a stock scheme, he and his daughter Meena stay at the Ponderosa with disruptive consequences. Luke turns the ranch into a casino and Meena continues her frantic search for a husband, where she left off in season eleven's "Meena".
Syndicate members Trask and Mason control the Syndicate's illegal racing operations, while Trask ruthlessly dispatches the competition - the IMF must take them out. Trask is jealous of thoroughbred owner Mason so Jim offers him a mysterious but promising racehorse - Trask finds out the horse is a kidnapped fast-racer. The IMF arrange for him to get the horse and then place a number of bets on the horse in Trask's name. After keeping Mason from having the horse killed, Trask's horse wins and the IMF get the $4 million from the Syndicate funds, leaving Trask to hold the bag.
When Edie is out of town, Lou hires Rhoda to redecorate his living room. However, Rhoda's tastes are too modern.
Everyone in the family is sick, so Edith calls Cousin Maude to help out.
Marcia makes a promise that she will get Davy Jones to perform at the prom. A promise she quickly learns is going to be very difficult to keep, since trying to get a hold of him is almost impossible.