The Bradys set out for a family vacation to the Grand Canyon. However, en route, the family stops in an old ghost town where an old prospector locks them in a jail cell.

Both Robert Reed puts in double duty as Grandpa Brady as does Florence Henderson when she portrays Grandma Hutchins in an episode where the Brady kids play matchmakers and try to get Grandpa Brady and Grandma Hutchins together. However, their efforts may all be for naught when an argument erupts between Grandma and Grandpa during a romantic dinner.

The Brady's friends, the Kellys are in the middle of adopting one little boy and soon find themselves adopting a total of three boys all of different ethnic backgrounds and they soon find themselves dealing with racist neighbors.

Carol breaks the news to Mike that she's expecting and an eavesdropping Bobby and Cindy assume that she's pregnant and pass it along to the rest of the family. Unknown to them what she meant was that she's expecting her nephew, Oliver to move in with them over the summer while his parents are in Africa.

When an FBI agent makes a visit to check Mike's security clearance, Bobby and Oliver both become convinced that Mike is working on some plans for a top secret project. They later become suspicious of Sam and become convinced that he plans to steal the ""secret plans"" and pass them on to the Russians.

Bobby, wanting to get rich quick, begins selling bottles of hair tonic and sells a bottle to Greg. However, Bobby runs for his life after the tonic turns Greg's hair orange, just days before his high school graduation.

Marcia plants a bogus story in her diary to bait Cindy after she gets fed up with Cindy's nonstop snooping. The bait is a story about Marcia contacting a talent scout after submitting a picture of Cindy and the talent scout wants Cindy to be the next Shirley Temple.

Cindy has been cast as the fairy princess in the school play. She's excited that her mom and new dad will be able to see her in the production until she learns she can only invite one parent. Torn between who she should choose, Cindy fakes an injury to get out of being in the play.

The day after Carol reads Mike's horoscope, which states "a strange woman will enter your life tomorrow," Beebe Gallini enters Mike's office and proves to be a most difficult client. Soon, Mike finds himself spending more time at the office than at home with Carol and the kids.

Carol is secretly writing an article about life with the Brady Bunch for Tomorrow's Woman Magazine. But soon after sending the article in, she gets a rejection letter.

Marcia has a crush on a boy who doesn't even know she's alive, at least not until she studies up on his favorite hobby, insect collecting.

After discovering he is the only Brady without a trophy, Bobby enters numerous contests in order to win one. Including, selling magazines and a televised ice cream eating contest.

Peter is stunned after he runs into a boy who looks exactly like him at school. His look alike comes in handy when Peter inadvertently makes two dates for the same night, one with Michelle and one that he forgot he promised with the niece of Mike's boss.

When Cindy's doll, Kitty Karry-All turns up missing, she accuses Bobby. This leads to a mock trial with Alice as the judge to determine Bobby's guilt or innocence. Then later Bobby's kazoo turns up missing and he blames Cindy.

When Bobby falls from a tree and sprains his ankle, he devolops a fear of heights. This prompts the Brady family to try to cure his fear.

After Bobby pushes Peter out of the way of a falling ladder, Peter volunteers to be Bobby's ""slave for life."" However, Bobby begins to take advantage of the situation which yet again leads to discord in the Brady household.

Jan becomes convinced she is a "no talent loser" after she fails to make it into a ballet recital which follows with her totally dropping out of ballet and on to tap dancing which totally drives the Brady family crazy.

Marcia and Jan mistakenly overhear Sam and Alice discussing elopement and jump to the conclusion that Sam and Alice are secretly planning to. This leads the Brady family to begin planning a wedding reception.

Surprisingly the ""once no talent,"" Jan is competing in a popularity contest at school. With Peter as her campaign manager and the rest of the family pitching in, she's got a great chance of winning. However, she quickly finds herself making promises to her classmates that she can't possibly keep.

With more and more of the girls belongings being moved over from storage, the boys become fed up and take to their 'No Girls Allowed' clubhouse in the backyard which sparks the first of many battles between the sexes. This leads the girls to try to build their own clubhouse.

Peter comes home from school with the measles, so naturally, Carol calls the doctor, her doctor, who happens to be a woman. Meanwhile, Mike calls his doctor, a man. Soon all the kids come down with the measles and the household is in an uproar in yet another battle of the sexes, as the girls want a female doctor and the boys want a male doctor.

Jan's practical joking puts Greg's science project, a mouse named Myron, in mortal danger when he gets loose allowing Alice to catch a glimpse of him which leads to her calling the exterminator.

When Bobby gets a set of drums he drives the family up the wall. Meanwhile, Peter is made fun of for being in the glee club by his football teammates.

Mike's boss, Mr. Phillips, invites him and his family on a fishing trip on his boat. However when Cindy comes down with tonsillitis, the trip is postponed. Tonsillitis quickly claims another, when Carol also must have her tonsils taken out.

An old boyfriend of Alice's, Mark Millard, comes to town and begins to wine and dine her, unknown to her he has other intentions in mind.