Papa returns from town and announces he placed a newspaper advertisement for a new wife and mother.

A woman named Sarah Wheaton from Maine responds to the advertisement, and the family begins exchanging letters.

Sarah agrees to visit the Whiting farm for a month and sends word that she sings.

Papa travels to the train station to collect Sarah while Anna and Caleb wait anxiously at home.

Sarah arrives at the farm with her cat Seal and brings sea gifts for each child.

Sarah bonds with the farm's dogs and sheep, gradually settling into her new surroundings.

Papa piles hay into a mound and covers it with a tarp, creating a dune for Sarah to slide down.

Neighbors Matthew and Maggie arrive with their daughters to help Papa plow the fields for corn.

Maggie encourages Sarah not to grieve leaving Maine, sharing that she also left a beloved home behind.

Sarah strides outside in overalls and insists that Papa teach her to ride a horse and drive the wagon.

A powerful storm batters the farm, forcing the family and all the animals to shelter overnight in the barn.

After replanting storm-damaged crops, Papa finally teaches Sarah to ride a horse and drive the wagon.

Sarah leaves alone in the wagon wearing her yellow bonnet, and the children fear she has gone for good.

Caleb spots a yellow bonnet returning in the dust, and Sarah comes home with sea-colored pencils, candles, and flower seeds.

Papa tells Anna and Caleb that he and Sarah will marry in the fall.

A lonely widowed farmer named Jacob Whiting places a newspaper advertisement seeking a wife and mother for his two children, Anna and Caleb. A spirited woman named Sarah Wheaton answers from Maine, and after an exchange of letters, she agrees to come visit the prairie farm for a month. Sarah arrives and gradually adapts to her new environment, bonding with the animals and learning the rhythms of farm life alongside the family. When neighbors visit and a fierce storm tests everyone's resilience, the family shelters together and emerges closer than before. After learning to drive the wagon, Sarah takes a solo trip to town, leaving the children terrified she has gone back to Maine for good. When her yellow bonnet reappears on the horizon and she returns with gifts that show her commitment, the family's future is sealed as Jacob announces they will marry in the fall.

The core story of how Sarah comes to join the Whiting family.

Caleb asks Anna why Papa stopped singing, and Anna explains their mother died the day after Caleb was born.

Anna reveals it took her three days after her brother's birth to decide she loved him.

Papa shows the children Sarah's first letter, in which she describes her life by the sea with her brother William.

Anna asks Sarah about braiding hair, and Sarah replies that her favorite colors are blue and gray like the sea.

Sarah sends Anna a book about sea birds, and Caleb treasures Sarah's letter so much he sleeps with it.

Sarah firmly insists that her cat Seal will live inside the house, not in the barn.

Sarah shares her sea shell collection with the children and teaches them to hold shells to their ears to hear the ocean.

Sarah cuts Caleb and Papa's hair and scatters the clippings into the wind for birds to use in their nests.

Sarah ties a ribbon in Anna's hair, and Anna glimpses herself in the mirror looking like Sarah's daughter.

Papa teaches Sarah to plow the fields with the horses Jack and Old Bess during the hot summer days.

Sarah takes Anna and Caleb to the cow pond and teaches them both to swim.

After the swimming lesson, the family lies on the grass and Sarah says the shimmering prairie reminds her of rolling ocean waves.

Maggie's daughters give Sarah three chickens as a gift, and Sarah clucks back at them and refuses to ever eat them.

Anna comforts Caleb by pointing out that Sarah would never have abandoned her beloved cat Seal.

Anna sets the table for four people while waiting and hoping for Sarah to return home.

Before Sarah ever arrives, the Whiting household is already shaped by grief — Caleb's questions about his mother's death and Anna's private sorrow reveal the family's deep need for healing. Through a series of letters, Sarah reveals her personality and the children reveal their hopes, setting the stage for her visit. Once Sarah arrives, the smaller daily moments — cutting hair, sharing sea shells, cooking together, swimming in the cow pond — are where the real family bonds form. Sarah's fierce attachment to her new chickens mirrors how she slowly learns to mother Anna and Caleb. When Sarah finally drives away in the wagon, Anna's quiet gestures of tending Sarah's plants and setting a hopeful table for four capture the depth of the family's longing. These secondary moments reveal that a grieving family is not mended by a single grand event, but by an accumulation of ordinary days shared together.

The quieter moments and small bonds that built a new family.

Caleb blurts out at dinner that he is disappointed Papa no longer sings, and Papa admits he has forgotten the words.

Anna recalls that her mother's last words were 'Isn't he beautiful?' and that she never said goodnight before her mother died.

Sarah describes herself as 'plain and tall' in a letter and says she will wear a yellow bonnet so Jacob can recognize her.

Anna worries Sarah will not want to leave her beloved sea for the flat, treeless prairie where the Whitings live.

When Sarah gazes silently at the flat land upon her arrival, Anna fears she will decide not to stay.

Sarah discovers a dead lamb in the field, furiously drives away the buzzards, and stays until Papa buries it.

After dinner, Sarah says 'Ayuh' and Papa and Caleb laugh and try out the unfamiliar Maine word.

In her letter to her brother William, Sarah calls the hay mound 'our dune,' which makes Caleb deeply happy.

Maggie offers to teach Sarah to drive the wagon so Sarah can come visit her, giving Sarah a reason to stay on the prairie.

Just before the rain arrives, Papa brings Sarah the first blooming roses of summer.

Sarah insists on helping repair the leaking roof and proves herself a skilled carpenter alongside Papa.

Sheltering in the barn during the storm, Caleb asks about the sea's storm colors and realizes Sarah has no pencils to match.

As the wagon disappears down the road, Anna is flooded with memories of the day her mother's body was carried away.

When Sarah returns, Caleb dissolves into tears and confesses he feared he was too loud and pesky for her to love.

Anna writes a final journal entry picturing all four seasons ahead and the songs — old ones and new — that Sarah will bring.

The story's emotional turning points begin before Sarah arrives, rooted in the Whiting family's unspoken grief and the silence where singing once lived. Sarah's early letters reveal someone honest about her identity — plain, tall, and unwilling to pretend otherwise — while her first silent gaze at the flat prairie sparks Anna's fear that she will never truly belong there. As Sarah's visit continues, small revelations deepen the bonds: a dead lamb shows her toughness, a shared Maine word breaks the ice, and a letter home signals she has begun to claim the prairie as her own. The storm chapter tests everyone, but it is Sarah's solo wagon journey that brings the family's deepest fears — and ultimately their greatest joy — to the surface. When she returns, Caleb's tearful outburst and Anna's private journal entry reveal just how profoundly Sarah's arrival has transformed this grieving household into a hopeful family.