Ruth and her sister Lucille grew up together as orphans, first under the care of their grandmother, Sylvia Foster. They were then cared for, briefly, by their two unmarried great-aunts, Lily and Nona Foster. Finally, their mother’s younger sister, Sylvie Fisher, took them in after Lily and Nana could not handle caring for them. The girls were raised—by these different women—in the house built by Ruth and Lucille’s grandfather, Edmund Foster. Longing for the mountains, Edmund had taken a train west to Fingerbone, Idaho, worked for the railroad, and prospered. He died in a train derailment on the bridge that crosses Fingerbone’s large glacial lake.

Ruth tells the following story about her family: Her newly widowed grandmother stays in Fingerbone and raises Molly, Helen, and Sylvie. After five years of quiet, orderly routine, the girls leave home. Molly goes to China as a missionary; Helen elopes with Reginald Stone to Seattle, becomes a single mother, and raises Ruth and Lucille with the help of a neighbor; and Sylvie marries a man named Fisher and becomes a drifter.

More than seven years later, Helen returns to Fingerbone with Ruth and Lucille, leaves them on their grandmother’s front porch, drives a borrowed Ford into the lake, and drowns. Grandmother Sylvia cares for the girls for five years before dying. Her unmarried sisters-in-law, Lily and Nona, come to care for the girls, but are overwhelmed. They send for Sylvie, the girls’ aunt, and flee when she arrives.

One week later, Fingerbone has a massive flood, and the waters reach the Fisher house. The extended family lives on the second floor for several days. Conflicts surface, as Lucille desires order, answers, and a conventional life and Sylvie desires a transient and unconventional life.

Lucille is falsely accused of cheating on a test at school and stays home “sick” for one week. When Sylvie writes a note to the school explaining that Lucille always feels better by midmorning, Lucille and Ruth keep the letter and spend the next week “playing hooky” at the lake. One day, they see their aunt walk onto the bridge. They fear that she is going to commit suicide. Although reassured by their aunt that she is not going to kill herself, they begin to think she is not stable. They return to school. Sylvie’s housekeeping eccentricities soon become apparent to the girls. Their aunt allows leaves and paper to gather in the corners of the home and takes the sofa outside to air out. She eats an odd assortment of cold foods with her fingers, in the dark.

By the second spring, Lucille is increasingly critical of Sylvie. She and Ruth stop going to school in March. They explore the woods—Ruth for her love of nature and Lucille to hide from the townsfolk. One Saturday, Ruth and Lucille spend the night in the woods rather than try to find their way back home in the dark after staying out too late. Lucille is anxious and fidgety; Ruth embraces the darkness, finding a balm to life’s losses. In the morning, Sylvie welcomes them home with quilts and tea. Ruth accepts, but Lucille does not. Lucille now embarks on a course of self-improvement and conformity, and Ruth finds comfort in Sylvie’s odd world. Conflicts continue, until one Saturday night Lucille leaves for good, moving in with her unmarried home-economics teacher.

The following Monday morning, Sylvie wakes Ruth very early. “Borrowing” a boat, Sylvie rows far out on the lake to a valley in the woods with a decaying house that Sylvie says is full of children. Ruth, left alone in the woods...