Bloodhounds chase twelve-year-old slave Moses as he follows the North Star to Pennsylvania on the Underground Railroad. His mother taught him to find the star before she was sold to a plantation hundreds of miles away. Finally in Harrisburg, Moses finds shelter with an abolitionist family, but when the Fugitive Slave Act becomes law, northerners caught harboring runaways must pay a fine and go to jail. Moses and a slave girl living with the family flee. They escape by canal boat, steamship, and rail, but slave catchers pursue them at every turn. Freedom in Canada seems far away. Will they ever reach it?