Separated from their brother, Alistair, on a summer's night, mouse siblings Alex and Alice embark on a determined rescue mission and investigate the activities of an elusive underground spy operation; while Alistair, who has encountered ginger-colored mouse Tibby Rose, tries to make sense of what has happened to him. Interest Level: 3-6 Reading Level: 5.8 ATOS Book Level: 5.8 AR Interest Level: MG AR Points: 9 AR Quiz: 151950EN.