The Bradys enter a road rally. However, the Wrong brothers steal parts of the gang's car to make an airplane.
The gang takes pity on a supposedly poor man, not realizing that he is actually the world's wealthiest man.
The Kids find out Marlon's birthday is coming up so they plan a surprise party for him but they don't know he's going to back in time to spend it with his old friend and fellow Wizard Merlin from King Arthur's court. But unfortunately his spell makes them switch places and Marlon keeps accidentally sending historic people into the future trying to get home.
When a television talent show comes to town, the kids all create their own individual acts so that they can enter.
The Brady kids meet Diana Prince (a.k.a. Wonder Woman), a university mathematician. Jan and Marcia are in the age old debate of Brains over Brawn. Marlon's magic accidentally transports them all back in time to ancient Greece where they arrive right in time not only for the Olympic games but to meet the famous mathematician Euclid.
The Brady Kids and Chuck go west to Fleetwood's Uncle Freddie's ranch to help at his big cattle drive, but it's only one steer they have to take care of. As they go on the drive they have to deal with Chuck's mischief making, cattle rustlers and then again Marlon's mixed up magic causes trouble by making the steer huge.
The Bradys try to stop a pair of thieves from stealing the crown jewels.
Greg, Marcia and Chuck are all running for class President and unfortunately this tears the kids apart. Greg and Marcia are coming up with great advertisements for their campaigns but Chuck manages to sabotage all of them without their knowledge, which tears the kids even more apart. Marlon finds out so with Moptop and the Pandas help they teach Chuck a lesson in honesty.
The gang accidentally gets a hold of a spaceship and winds up befriending some little men from Venus.
Greg has to learn to ski in order to compete in a race against Chuck. Marlon's magic only makes things worse.
The gang enters their animals in a pet show but Marlon refuses to participate. Moptop falls in love with Babs French Poodle and Marlon's magic accidentally transforms her into a pretty lady who barks.
The Brady Kids visit a soda pop plant and Marlon is accidentally sealed in a can and the gang has the hardest time trying to rescue him.
Cindy meets Clark Kent and gets him to talk about the city's "Paint-Up" week on TV to advertise for help. Clark and Lois Lane are also going participate. But the criminal scientist Wily Toulouse La Trick and his henchman Igor substitute delayed-action invisible paint so that when the bank is painted it will become invisible so they can rob it.
Bobby is a fan of the Lone Ranger and orders a pin from his fan club. Marlon uses his magic to try to transform it into real silver but bring the Long Ranger's horse "Silver" to the tree house.
Peter wishes he looked like the movie star Clint Flint. Marlon uses his magic to grant his wish but screws up and morphs Bobby's body into Flint's and vice versa.
The Brady Kids and their newfound friends escape giant crabs and discover that Ping and Pong are two test pandas with an experimental rocket capsule. Then they meet Father Nature, who is charge of the weather because his wife Mother Nature is sick, as well as the Abominable Snowman who is unhappy because of the tropical island's heat. Marlon tricks Father Nature into creating snow on the island. To get back home, they decide to launch the pandas' rocket into the ocean and us it as a submarine to sail home.
The Brady Kids enter a Hot Air Balloon race at the local carnival. Several of their school friends are on another Balloon. But something goes wrong and the balloon takes the group to a strange, far-away island where they meet Marlon, a magical Mynah bird whose talents include ventriloquism and impersonations; and Ping and Pong, two pandas who speak only Chinese.
