Season 4

When Laura's dog, Jack, dies, her Pa gives her a new dog, Bandit, after the dog follows him home. Although the dog seems very friendly to Laura, Laura doesn't want it. When Laura later visits Aunt Kezia, a lonely women, she realizes that she really loves Bandit.

After going to Chicago for the first time, Charles and Mary are very disappointed in what life in the city is really like.

A mother is in deep denial over her daughter's death in a tragic drowning. To comfort herself, she kidnaps Laura, hoping she will take her late daughter's place.

Charles must take a delivery to Mankato immediately and is unable to finish the addition to his house. Caroline hires a handsome man, Chris, to finish the house. Mary suspects that her Ma and Chris are falling in love.

Charles and Caroline go away and leave Mary in charge. Laura and Andy find some baby wolves.

Things are being stolen in Walnut Grove. Laura and Andy try to figure out who's the crook. They end up getting a lot of people mad at them, including Mr. Ingalls, especially after his hair turns green.

When Doc Baker is unable to save a patient of his, he believes that he is unhappy being a doctor. He finds a new doctor for the town. Doc Baker stays on when he realizes that the new doctor really doesn't care about his patients.

Jesse and Frank James hide out in Walnut Grove. The people of Walnut Grove find out who they really are when bounty hunters come looking for them.

People in Walnut Grove are betting on a big boxing match in town. Mr. Ingalls does not know that he will be fighting an extremely sick person. That's why Charles is surprised in the ring when he is able to defeat his opponent so quickly. After his opponent collapses, he is brought to Doc Baker. Doc Baker is able to save him but warns him that he needs to stop fighting.

The Ingallses and Olesons take a trip to the fair. Patrick, a carnival worker and Mary's boyfriend, and his boss, Cass (a balloonist and suave ladies man) vie for Mary's attention; Charles and Nels entering a jackass riding contest; and Carrie has her own adventure.

Adam Simms and his son Luke move into town. Adam falls in love with Miss Beadle, while Luke and Nellie Oleson fall for each other. After Miss Beadle talks to Nellie about love and marriage, Nellie and Luke decide to get married.

An Indian boy comes to Walnut Grove trying to get help for his sick father. The people of Walnut Grove become very hostile toward the Indians. Thanks to Mr. Ingalls' help the Indians are able to escape.

Mary eagerly accepts a teaching job in a backwoods community, only to face the sternest test of her career and life when she meets the community's leader: an elderly woman who is totally against education but has concealed a shameful secret.

Mr. Ingalls is severely delayed when a wheel breaks on his wagon in the pouring rain. This is the day of Charles and Caroline's wedding anniversary. Everything had been all prepared and set up for that day. When Charles doesn't show up in time, Caroline tells the children how hard it was to get Charles to notice her and how many heartbreaks she had before she finally knew that Charles loved her.

When Laura is playing along a creek, she finds a bottle with a note in it. The note read, ""Be my friend."" Laura convinces Pa to help her look for the person who sent the note. They end up finding a baby. Charles then searches for the parents of the child. The baby belongs to teen parents. The reason the mother left the baby for the Ingalls to find was because her dad was opposed to her being with the guy she conceived the child with. The young parents take the baby and try things again.

Mrs. Olesen may finally get to drive those ""homely"" Ingalls from Walnut Grove for good when the family gets an inheritance from a wealthy relative. Against their better judgement, Charles spends the money on farm equipment and other things before finding out he used worthless Confederate funds to make the purchases.

Nels' brother sends his 12-year-old son to Walnut Grove after repeated conflicts at home and school. When Mrs. Oleson interferes in her husband's plans to rehabilitate his nephew, Nels asks Charles to step in and teach the boy some values.

Charles and Caroline are going to have another baby. Caroline constantly refers to the baby as he. Caroline delivers the baby sooner than expected causing Charles to be the doctor. The baby ends up being a girl, Grace.

Mary falls in love with Seth. When Mary's eyesight starts to get worse, Charles takes her to a specialist. He is devastated when the specialist tells him that Mary will lose her sight. Charles is unable to tell Mary for a while that she is going blind. When Mary does go blind, the whole family suffers.

Charles and Caroline sign Mary up for the blind school in Iowa. At first, Mary is very reluctant to learn anything at the school. However, after being with her teacher, Adam Kendall, for a while, she turns her outlook on life around. Mary is such a great student that Adam asks her to help her teach at a blind school with him.