The novel tells the story of three siblings, Eily, Michael and Peggy O'Driscoll, who live in a small cottage in rural Ireland. At the opening of the book, in 1845, blight strikes the family potato plot, and shows the beginning of the Great Famine. Their baby sister Bridget dies of sickness and is buried under the hawthorn tree in the garden: in Irish mythology, the hawthorn is linked with the otherworld.
Their father goes to find work fixing the roads, and the children and their heart broken mother struggle each day, getting barely enough food to survive. Their poor mother ends up selling all of her belongings except for the clothes on her skin. Finally, impatient and worried, she leaves to search for her husband. After several weeks of waiting for their parents, the three siblings come to terms with the fact that their parents have died. This is when they make their long journey to the other side of Ireland, in search of the long-lost aunts (the only other family members they know of) who they only knew because of their mother's stories. With no exact location or map to follow, no adult and no food, these three siblings try to find their way "home".