Two girls， one black， the other white， flee from the South to the North in a novel set during the Civil War. Reprint.，Forty years after Susannah， the ward of a slave owner， helps Bethlehem， a slave girl， escape to freedom， Susannah's granddaughter， Mary， and Bethlehem's pupil， Free， learn the story of the heroic escape，In 1855 two thirteen-year-old girls， one white and one black， run away from a southern farm and make the difficult journey north to freedom， living to recount their story forty-one years later to two similar young girls.