The year is 1848. It is a time when magic and ghosts exist. Four Magnificent Children are captured by Badblood's Circus. Theo can look into your eyes and reveal your secret thoughts, which come out of his mouth like a swarm of bees. Ginny has a bird called Blue living inside her. Her ribs are woven together to form a birdcage. Blue perches on a swing made from one of her ribs. And the Thought-reading Twins, Archie and Millie Luxbridge, have an extraordinary ability to read each other's minds. They become stars of the circus but are unaware that Badblood has a dark and secret plan. One hundred years later the children's ghosts appear on an island off the coast of Ireland where a boy called Rua befriends them. Rua discovers that a terrible fate awaits them and, in a desperate race against time, he struggles to learn how they may be saved.