This is a cute mystery aimed at the age 10 and up set. Youngsters Amy and James follow their cat, Kiwi, when she leaves home one night; they've been curious about where she goes.Imagine their surprise when they are turned into kittens so that they can follow her to Cat City to help her figure out why cats are being abducted from the streets. With the reverse anthropomorphism, Johnstone writes cleverly about the childrens' difficulty learning how to navigate with four legs and a tail. She also occasionally breaks the fourth wall, addressing the reader with questions like "Have you ever seen a cat in a waistcoat? Nope, me either."The book is not too scary, and things are resolved easily. The book does leave a bit of a cliffhanger to be resolved in a subsequent volume, "Kiwi and the Missing Magic."Cute book for young animal lovers and budding mystery buffs.