An eccentric old woman who has set up her "house" in the center of town and a stray dog who hitches a ride to Plum Creek from Mankato in Charles Ingalls' wagon both, in their own way, help Laura through the loss of an old friend and teach her and rest Walnut Grove lessons in love and acceptance.

An excited Mary Ingalls accompanies her father to the Chicago Grange Convention to surprise her true love, John Edwards, by accepting his invitation to a cotillion in person. But, surprises are in store for everyone as both Charles and Mary experience a trip very different from the one they each expected.

After eleven year old Ellen Taylor accidentally drowns while swimming on a hot summer day with the Ingalls girls, her grief-stricken mother, Eloise, first blames Laura for asking Ellen to go to the pond with them and then, unable to accept the reality of her little girl's death, begins to imagine that Laura is Ellen.

Meddling Mrs. Oleson starts tongues wagging when a handsome itinerant handyman stays in the Ingalls' soddie (storeroom) while helping Caroline with a kitchen addition after Charles is called out of town to work on Mr. Hanson's railroad lumber contract.

Laura and Andy find a Mama in a trap and two pups nearby. They take the "dogs" home, only to find out they are wolves. At the same time, some dogs that used to be pets but were released to the wild have gotten really wild and have been attacking some livestock in town. Charles and Caroline have gone out of town and Mary is left in charge of Laura and Carrie. She is under stress so she is a little too bossy and Laura runs to her tree house as often as possible or hangs out with Andy. They overhear that Jud Larabee (whose livestock was attacked) knows about their wolves and thinking they are responsible is going to come and kill the wolves. So, Laura and Andy move the wolves to Laura's barn. While out there, Carrie and Mary hear the dogs coming and they all go to the barn and end up trapped in the loft because the dogs burrow under the door and get in. The local farmers come to the rescue and kill the dogs and find out that the mama wolf actually saved Andy's life!

Junior detectives Andy and Laura take tips from fictional sleuth Farnsdale Fremont of Scotland Yard to track down the mysterious Walnut Grove chicken thief, ruffling a few feathers of their own along the way.

Holding himself responsible for a farmer friend's death and unable to face the man's seven-months-pregnant widow, disheartened Doc Baker leaves his Walnut Grove practice in the hands of a self-absorbed Philadelphia physician and decides to raise corn.

As Walnut Grove school begins to study the Civil War, Mary Ingalls unexpectedly learns firsthand information when she starts running errands for two mysterious newcomers who sided with the South. But Mr. Hobbs and Mr. Dankworth are hiding more than just their war affiliation and the whole town comes under siege when an overzealous posse rides in, prepared to capture them at any cost.

After the Garveys' grain-filled barn burns down and leaves them with no crop to sell, proud Jonathan refuses to accept help from anyone, even his wife Alice, and their marriage is put to the test when neither half of the stubborn couple will consider the other's solution to the problem.

A road-weary, aging boxer who has sacrificed his family and his health for the only career he has ever known, comes to a long-dreaded crossroads when he unexpectedly meets his match in a ring in Walnut Grove.

The Ingalls and others from Walnut Grove go to the fair. Mary finds her friend Patrick who happens to be working for the balloon show. Since somehow a pickpocket has stolen his wallet, his coworker, Cass McCray agrees to take Mary around and buy her some goodies. Laura plays a shell game and quickly uses up her money. To make some more, she agrees to sit in the dunking booth. After she has sat there for 30 minutes, Nellie comes along to taunt her. At the same time, Laura realizes that two guys are coming that are sure to have a good arm, so she tells Nellie that the game is rigged and she just has to act scared and if she wants, she'll let Nellie work the second half of her hour. Sure enough, Nellie goes down on the first shot. Caroline is trying to get her entries registered in the canned vegetables and so Carrie has to wait with her. Charles and Nels rope and ride a wild mule and win some money. Her parents ask Laura to take Carrie to the merry-go-round. While they are in line, the balloon starts to lift off, so Laura goes to go watch it, leaving Carrie with no money for the ride. Charles gets angry and orders Laura to take Carrie on the ride. He also tells her that if she finds Bandit, to tether him to the wagon. So, they try again, but Laura sees Bandit and chases after him, again leaving Carrie with no money. She wanders off and sees a balloon basket and gets in and lies down. Patrick, jealous of the time Cass is spending with Mary cuts the balloon loose, not realizing that Carrie is sleeping inside.

Adam & Luke Simms move to Walnut Grove. Luke falls in love with Nellie. Nellie likes him but he doesn't like to wear shoes and he wears overalls without a shirt over his long underwear, so Harriet thinks he is beneath her and demands that Nellie stop seeing them. Luke gets Mary to help him pick out a ring for Nellie's birthday and Nellie thinks Luke was playing with her affections. Nellie cries to Miss Beadle and Miss Beadle goes to Mr. Simms to tell him that she won't have that kind of treatment in her school. Mr. Simms explains the situation and Miss Beadle starts to fall in love with Adam Simms. Luke and Nellie decide that they are going to elope. They get married and go to the hotel. That is where Harriet, Nels, Adam, and Ms. Beadle find them. They take them back to the Justice of the Peace and have him un-marry Luke and Nellie, but while they are there, Adam Simms and Eva Beadle get married.

An Indian chief needs help from a white man's doctor and the closest town is Walnut Grove. Most of the townspeople want to massacre the Indians because of what other Indians had done to them in the past. Charles and Dr. Baker take the chief, his adult son (acting chief) and his son's two children to Ingalls' house to stay until the chief is well enough to travel. Unfortunately, some of the townspeople find out that the chief is there and they want to come kill him, so Charles transports them to safety.

Charles Ingalls and Jonathan Garvey are trying to win a contract for a freight operation. So, it means they will be making good money but they will be on the road for usually two weeks at a time, and usually with only an overnight layover. Caroline feels that this new job is her rival. Jimmy Hill is Laura's friend. They go frogging together and Laura falls in the creek, and Jimmy pulls her out, and for the first time, we see Laura liking a boy because she is a girl. The next day, Laura decides to wear her hair down because it makes her look more grown up and she wears her Sunday pinafore over her school dress and her Sunday hair ribbons. Of course, this means she can't play games at recess. Samantha Higgins is a new girl at school and since she is wearing overalls, has her hair braided and is considered tomboyish, Jimmy Hill invites her to play ball with them. Laura considers her a rival.

On Rev. Alden's recommendation, Mary is hired as a teacher in a small backwoods community called Willow Run. There, she is met with pure hatred from its town leader, Miss Peel, an elderly woman who is fiercely opposed to the school. Miss Peel's determination to drive Mary from town proves to be a severe test to the Ingalls girl's resolve and character.

Traveling Charles Ingalls struggles with a broken wagon wheel and bad weather trying to get home in time to celebrate his wedding anniversary while, back in Plum Creek, waiting wife Caroline tries to keep worry at bay by entertaining their daughters with the tale of another time she was kept waiting and how she and their father first met.

After finding a number of bottles containing messages, including a photograph, from a mysterious girl, Laura finds an abandoned baby. Laura takes the child in and cares for it like it was her own, not knowing it belongs to a timid young woman with an abusive father.

In this episode, Charles receives word of an inheritance from an eccentric uncle. Soon, the whole town is abuzz, eagerly helping the initially reluctant Ingalls family spend the promised money. As the debt rises, so does Charles' discomfiture...until the consequences of the blessing make it feel more like a curse.

When young Peter Lundstrom is expelled from his private school for petty theft, his wealthy father sends the boy to stay with Uncle Nels Oleson in Walnut Grove for a long-overdue lesson in values.

A misinterpreted remark from husband Charles plants a seed of worry in newly pregnant Caroline Ingalls that he will be disappointed if the baby isn't a boy.

Long hours studying by candlelight for the state teacher's exam results in tired, blurry eyes for Mary Ingalls, prompting a routine visit to the eye doctor; but when Charles is told that Mary's worsening sight is just the beginning of a much more serious problem, the concerned father can't bring himself to tell his beloved daughter that she will, most certainly, soon be completely blind.

Feeling lost and abandoned, Mary Ingalls battles anger and self-pity at a school for the blind, far away from the little house by Plum Creek. But soon, Mary finds a source of hope in her new teacher, Adam Kendall, and as the two young people work together they find they have much in common. Meanwhile, back in Walnut Grove, many are forced to consider the real possibility of having to start a new life elsewhere as the town's economy erodes and work becomes scarce.