After a buggy accident hurts Miss Beadle, the school board decides that Caroline is best qualified to temporarily replace her. Caroline is hesitant to do so however, until Mrs. Oleson demands assurance that she will not show favoritism to her own children. Nellie tries to stir up the students to rebel against Caroline until Caroline bests one of them in a contest. Even though Laura tries to warn her, she forces slow student Abel Makay to read in class, embarrassing him in the process. Mary and Laura tell her that Abel can't read and that Miss Beadle had problems with him too.
Caroline confers with Miss Beadle about Abel Makay. Miss Beadle tells her that is not backward--just shy. Back home, when Laura refers to Abel as Dumb Abel, Caroline is furious, and determined to find a way to teach Abel to read. Charles is proud of her. When Caroline brings the eggs to Oleson's, Mrs. Oleson decides to offer more for the eggs in exchange for assigning her children as monitors. Caroline points out that the monitors are for the disinterested children so Mrs. Oleson backs down. At school, Caroline finds Abel Makay is absent so she visits his father after school. Mr. Makay is gruff but he tells her that she has to convince Abel to go back. When Caroline sees Abel's artistic talent, she convinces him to return.
The next day, Caroline gathers the students and asks them if they are willing to help her teach Abel to read. They agree. After lunch, Abel returns to school as agreed. Each student is assigned a specific letter and when called upon, they will stand, hold a sign showing the letter they represent and sounding out the letter. The last student for a particular word will sound out all of the letters and say the word. Abel is assigned the letter "T." Within a few minutes, Abel is sounding out and saying words. After school, Caroline tells Charles she went from her worst day to her best. The next day, the class is reciting common words that Caroline holds up flash-card-style. Mrs. Oleson comes in after Abel's turn and ridicules the boy and Caroline's attempt to teach him. Abel runs out and Caroline dismisses school, quitting in the process.
That afternoon, the school board arrives at the Ingalls farm and tries to get Caroline to return to the school. Caroline sets them straight on the events that prompted her resignation and Mrs. Oleson is shamed into silence. However, despite their entreaties, Caroline declines. When Mrs. Oleson decides to teach school, herself, Caroline decides to keep her kids home. She regrets her decision to quit. The next day, Caroline goes into town to sell her eggs. Mr. Oleson gives her the same price as last time even though he realizes she is no longer teaching. The only kids who show up at school are Mrs. Oleson's and Caroline, standing on the steps of the Mercantile, has the satisfaction of seeing this--to Mrs. Oleson's apparent dismay. On her way home, Caroline sees Abel who refuses to return to school but instead gives Caroline some carvings of the letters of the alphabet--so she can use them in school. Caroline tells Abel she won't go back to school unless he goes back.
At school the next day, Abel is dividing words into syllables. Soon, Abel has caught up to most of the kids in class. On Caroline's last day of school, she hands the reins back over to Miss Beadle who tells her that Abel Makay has something he would like to read for her. It is a short but stirring thank you for her work and dedication. The class gives her a standing ovation as she walks out.