Alexandra, a tall, strong girl of twenty and her five-year-old brother Emil live on a farm. They are in the small town of Hanover, Nebraska, one blustery winter day. Alexandra has seen a doctor who says there is no hope for their father. Emil's kitten gets stuck up a tree and a teenage boy named Carl Linstrum gets him down. They amuse themselves by watching a beautiful little Bohemian girl named Marie.

Their father, John Bergson, is indeed dying at age forty-six. He calls together Alexandra and her three brothers (Lou, Oscar and Emil). Although Lou and Oscar are seventeen and nineteen years old, he is entrusting the farm to Alexandra.

Alexandra does well for three years until there is a bad drought. Many families in the area give up and move, including the Linstrums. In contrast, Alexandra decides to buy even more land while it is cheap. She is open-minded and plants new varieties of crops; she is the first to build a silo. She even takes advice on animals from Crazy Ivar, a local insane hermit who has magical curative powers.

Sixteen years later and partly because of her visionary ways, Alexandra has the largest, most prosperous farm in the Divide. She is devoted to Emil's care and education and makes sure he goes to college, against the advice of Lou and Oscar.

Meanwhile, Emil has fallen in love with the beautiful little girl of Chapter l. Marie is now married to Frank Shabata, a cruel, hot-tempered man who is jealous of her beauty and natural happiness. Marie and Alexandra are close friends but Marie does not confide that she is in love with Emil and Alexandra does not suspect.

Carl shows up unexpectedly and stays a month with Alexandra. Lou and Oscar confront their sister and later Carl. They think Carl is after the Bergson property and most of it is rightfully theirs. Carl leaves town because he is afraid that Alexandra is too strong and wealthy for him.

Emil celebrates the wedding of his best friend Amedee to Angelique. The joy of the newlyweds depresses Emil; to him, love is only torment. After his college graduation, he goes to Mexico for a year.

When he returns, the attraction between him and Marie is as strong as ever. At a church festival, they secretly share a kiss. Emil meets her privately and tells her that if she will not run away with him, he must leave: it is too much torment to be near her.

As Emil is about to leave again, Amedee dies suddenly. At his funeral Emil has an epiphany and seeks out Marie. He finds her asleep under a mulberry tree. They embrace and make love. Frank shoots and kills them both in a rage.

After the murders, Alexandra falls into despair. The person she has lived her life for is dead, as well as her best friend. She deliberately seeks out Frank Shabata and visits him in prison.

Soon afterwards Carl returns to the Divide. He realizes that Alexandra needs him and the novel ends with their union.