Thea Stilton and the secret city Thea Stilton and the secret city / Thea Stilton and the star castaways Thea Stilton and the Missing Myth Thea Stilton and the Lost Letters Thea Stilton and the ice treasure Thea Stilton and the lost letters Thea Stilton and the missing myth Thea Stilton and the ice treasure / Quest for the secret city