Twelve-year-old Jake moves from Boston to the rural port town of Wicasset, Maine, with his mother, father, and six-year-old brother, who has "fits" as a result of what we now know to be cerebral palsy. The family keeps Frankie hidden, because neighbors in Boston regarded his disease as evidence of some wrongdoing on the parents' part and shunned them. It is 1838, and the father has lost his job in a bank because of the "Panic of 1837," and takes a job at a lumber mill for which he is ill suited. As the job keeps him away except for weekends, Jake has to learn how to gather food, fuel, and local information to care for his mother and brother in a small, drafty house.

He gets to know neighbor children whose mother remains hidden because, as he later learns, she is a hopeless alcoholic. Eventually he gets a job with the schoolmaster/jailer, befriends a mentally handicapped young man with no home, and gets to know the local doctor who persuades him that the community will accept his brother and family, and that their secret need not remain hidden. After weeks upstate on a logging trip, the father comes home with an arm crushed in an accident. The doctor helps him find work as a clerk in the custom house.

In the father's absence, in addition to his other accomplishments, Jake helped prison inmates and the schoolmaster/jailer's family escape a burning building, winning the gratitude and respect of the townspeople. On his father's return and promise of new work, he has renewed hope of private tutoring that might prepare him for college despite the family's poverty.