This is a story of a girl Assol, a sailor's daughter, ostracized by her village because of her father's (justified) actions, who is told by an old storyteller on an old man's whim that someday a ship under scarlet sails would come to take her away. This is a story of Arthur Gray, a boy from a rich family (in a castle!) who is noble and kind and dreams of becoming a sea captain. One day, their paths are meant to intersect and they will find happiness.
It speaks to those who have ever felt that they don't fully belong in the world they live in, that they are meant to do something else, to experience other horizons beyond their houses and offices and routine lives.
It's terrific story about love! Well written, innocent enough for kids but romantic enough for adults, short enough that you don't have to invest much time, but long enough for an evening or two. Highly recommended.