Caleb and Anna have been living without a mother for a long time. In fact, Caleb doesn't even remember Mama, who died a day after he was born. Anna tells him that Papa and Mama sang every day, and now Papa doesn't sing at all. To remedy this situation, their father places an advertisement in a newspaper for a mail-order bride to come live with them in their prairie home.
All the way from Maine, a woman named Sarah answers the ad. Caleb wants to know if Sarah snores. Anna wants most of all to know if Sarah sings. Sarah makes plans to arrive, and writes, "I will come by train. I will wear a yellow bonnet. I am plain and tall."
So the family waits. In the spring, she comes with her cat named Seal, gray like the seals that swim near her seaside home...and a sea stone, which she eventually gives to Anna. Jacob, the father, teaches Sarah some skills for the farm, like driving a tractor. Everyone hopes she will stay, most of all Caleb and Anna, but Sarah misses the sea, her brother and her three old aunts.
One day Sarah takes the wagon alone to town, and Caleb and Anna worry. What if she doesn't come back?
Newbery Medal Winner, 1986 Scott O'Dell Award for Historical Fiction for Children, 1986