Lynne Jonell

Ten-year-old Christina lives a sheltered life until she discovers a secret tunnel, an evil plot to enslave orphans, and a mysterious source of energy known as zoom.

Duncan, eleven, is very smart with the rare ability to speak Cat, but his mother has always insisted he appear only average, and when a perfect test score draws attention to him, he not only discovers the wisdom of his mother's rules, he finds himself crossing the seas on a quest for his true identity.

Ten-year-old Emmy and her rodent friends must fend off the evil former nanny, Miss Barmy, as they search for Ratty's missing mother.