In the schoolyard, Nellie and Laura are captains for a relay race. Laura's team is one player short but Laura runs two legs and her team still wins. When they get home from school, they learn they've been invited to Nellie's birthday party. Mary is excited to see the inside of the Oleson's house but Laura is not so much. At the Nordstrom's, Olga's grandmother, Helga, is helping her get ready for the party but her father, Jon, is reluctant to let her go, knowing that her handicap (Olga was born with one leg shorter than the other) will subject her to possible ridicule from the other children. The Ingalls' girls arrive at the Oleson's for the party and both are agog with wonder when they see the house's furnishings. Willie and Nellie are fussing over their toys and refusing to let the girls play with any of them. When Nellie shows them her newest doll, Laura accidentally rips the doll's dress earning her a twisted ankle when Nellie pushes her. The kids go outside to play but Laura is limping so she hangs with Olga. She asks Olga about her leg and then they both go play around the mill. When Olga returns from the party, her father questions her enjoyment at the party. At home, Charles and Caroline discuss Laura's injury and the possibility of the girls hosting their own party. Mary promises to ask the girls on Monday. Laura suggests that it would be great if Nellie said no. On Monday afternoon, Mary is walking home with Olga having gotten acceptances from all of the girls they invited. Olga thinks Nellie is lonely. Laura asks Pa what makes cripples. She mentions Olga's deficiency and that Olga didn't seem to limp when she walked on some boards by Hanson's mill. Charles gets the idea that he could make a special shoe for Olga and he goes over to the Nordstroms to talk about it. However, Jon rebuffs his offer, accepting his daughter's condition. Later, Caroline is helping Charles on the crosscut saw when Helga and Olga Nordstrom appear. Helga gives him a pair of Olga's shoes. Charles makes a platform for Olga's right shoe. At the Nordstrom's, Inga is getting ready to attend the Ingalls' party. At the Ingalls', Inga tries on the platform shoe and walks around the room without limping. Laura proclaims it a miracle and she and Mary take Olga outside to practice running on the shoe before the other girls get there. The other girls arrive at the Ingalls and Laura whispers to Olga to wait until all the girls are in the loft and then to go out into the yard and wait for them to come out and play Three-A-Cat. The girls go outside and Laura announces that she and Nellie will pick teams. Nellie picks Mary and Laura picks Olga and they alternate until they have four girls each. When play starts, Olga bats first, gets a hit and circles the bases before Nellie can get the ball back in. Play continues until Nellie grows tired. She looks at Olga's shoes and decides it would be fun to take off their shoes and go wading in the creek. Laura tells Olga she will play with her but Olga convinces her to go ahead. At the creek, Laura entices Nellie to the spot where the crab lurks and Nellie is scared and falls into the creek to the utter enjoyment of the other girls. Jon Nordstrom can't find Olga's other pair of shoes and Helga admits she gave them to Ingalls. Jon heads over to the Ingalls farm and starts a fight with Charles until he hears the girls calling to Olga to join them in their game. He looks up and is surprised to see her running and playing like a normal child. Olga spots him, runs up and gives him a hug and asks him if he saw her running and playing. When the party is over, Laura tells her Pa that she and Mary will walk back a little ways with their guests. Inga asks her Pa if she can go, too. He agrees. He apologizes to Charles.