Their mother died the day Caleb was born. Their home on the prairie is quiet now and Papa doesn't sing anymore. Then Papa puts an ad in the paper for a wife and receives a letter from one, Sarah Elizabeth Wheaton of Maine. Papa, Anna and Caleb write back and Sarah decides to visit for one month. She writes, "I will come by train. I will wear a yellow bonnet. I am plain and tall and tell them I sing." Will Sarah be nice? Will she like them? Will she stay?