The book tells the story of Ellen and William Craft's mission to cross state lines in order to become free. In this escape they take advantage of Ellens paler skin and disguises her as a white gentleman traveling with his slave (her husband). 

The story is true and the people they meet along the way are also real. Despite the context the story has a great deal of humor reflected in the characters and the great length they go to keep their identities a secret. This combination reminded me of a Dickens story in all the best ways.