Trying to interest his newly adopted son in more "manly" pursuits than reading and writing poetry, Isaiah Edwards buys a rifle for John Jr.'s birthday and stubbornly insists that the two of them go turkey hunting, even though the sensitive teenager has made it plain that he doesn't want to go. But a life-threatening situation during the hunt and a secret revealed afterward, result in a life-changing event for both of them.
Mary worries that she'll disappoint Walnut Grove if she doesn't place first in the state mathematics competition after the community pays her way to represent them; meanwhile Laura's feelings of jealousy towards her older sister are soothed and she begins to feel more grown-up after her wise Pa asks her to take charge of the Ingalls household while Caroline accompanies Mary to Minneapolis.
Caroline Ingalls sends her family on ahead to the picnic grounds for the week-end, planning to join them after baking pies for a church fund-raiser, unaware that a simple scratch on her leg is quickly festering into a life-threatening infection.
While on a trip to Springfield, Carl Edwards accidentally releases the brake on a caboose that he, Mary and Laura are exploring, sending the lone car and the terrified trio hurtling down the tracks towards an oncoming express train.
When teacher, Miss Beadle, is deemed unable to control some of the rowdy, older boys in her class, Mrs. Oleson convinces the Walnut Grove school board to replace her with a firmer, male hand. But the new schoolmaster tries to bully his students into submission and singles little Laura out as a troublemaker, blaming and punishing her for the slightest infraction even when she isn't the one responsible.
When their grain doesn't sell for enough to see their families through the winter, Charles and Isaiah hire on with the railroad to haul a wagon-load of highly explosive nitroglycerin over a treacherous mountain road and, as their journey progresses, find themselves dealing with situations almost as volatile as the freight they so carefully carry.
Caroline and the girls can't help but think the worst when Charles begins to behave mysteriously and later lies about the amount of time he has spent doing carpentry work for their lovely, young neighbor, the widow Elizabeth Thurman.
An immigrant family provides an example of thankfulness and a reminder that freedom isn't free after a property tax increase leaves most of Walnut Grove in no mood to celebrate the United States' 100th birthday.
Coming home after 12 years of performing with a busy Philadelphia orchestra, Mrs. Whipple's troubled son, Granville, hopes that the peace of Walnut Grove will help him shake the nightmares and the morphine addiction that resulted from an incident during the Civil War Battle of Shiloh.
Overwhelmed by the senseless destruction left in the wake of a devastating tornado, a bone-weary Charles Ingalls convinces himself to give up trying to make a life for his family on an unforgiving prairie, puts the farm up for sale and prepares to move back to the big woods where he was born.
After rescuing a seriously ill, unconscious Reverend Alden from his runaway wagon, down on his luck plainsman, Caleb Hodgekiss, puts on the clergyman's collar and devises a plan to fleece the charitable townsfolk of Walnut Grove.
When Nellie Oleson is seriously injured after falling from Bunny, a horse that used to belong to Laura Ingalls, Nellie's mother blames Laura for the accident and orders the animal destroyed. But Laura secretly steals her still-beloved Bunny away from Mrs. Oleson's vengeance and resigns herself to the penance of waiting hand and foot on a demanding, bedridden Nellie.
Conniving Mrs. Oleson is so certain that her scheming and daughter Nellie's new thoroughbred racehorse will beat Laura Ingall's speedy mount, Bunny, in the Hero Township horse race that she puts up a valuable family heirloom as first prize.
Passing the Oleson's house while out with Mary for a night of window soaping on a spooky Halloween eve, Laura hears a loud argument and peers in the window just in time to witness Mr. Oleson swing his sword... and cut off Mrs. Oleson's head!
After a letter from Wisconsin brings the sad news of his mother's death, a grieving Charles travels back to his boyhood home in the big woods, hoping to convince his heartbroken father to return with him to Walnut Grove.
Life in Walnut Grove with Charles, Caroline and three active grandchildren seems to be just the tonic Grandpa Ingalls needs to help him recover from his wife's death until a broken promise after a terrible accident reopens an old wound and drives a wedge between him and granddaughter Laura.
To save him from Farmer Parsons shotgun, Laura takes a cantankerous billy goat in trade for doing chores for Mrs. Parsons, names him Fred, and finds, much to her dismay, that mischievous Fred's constant companion is trouble.
Following Reverend Alden's lead, the Walnut Grove townsfolk try to turn the other cheek when the bad behavior of the recently arrived Galender brothers causes tempers to flare, until a series of incidents begins to reveal the trio's more sinister nature.
Laura feels like she has grown enough to go hunting with Charles so they let her. While unrolling the bedroll, she accidentally knocks over the gun that Charles left loaded and ready to shoot. It goes off, hitting Charles in the abdomen. Laura has to try to help him back to the trapper's cabin. She manages to get him on his horse, but when they are going up a hill, it's too steep and the horse and Charles slide back down the hill. The horse dies. Charles sends Laura to the cabin to get help. She gets their and the trapper has gone off to check his traps and only his ...