Gillian Cross first got the idea for Wolf when she saw people keeping ocelots (small, wild South American cats) in cages as pets in America. She wondered what would happen if one of them escaped. She never wrote that story, but kept thinking about the image of something savage and dangerous lurking in an ordinary urban environment. This adventure begins when fourteen year-old Cassie is sent by her grandmother to stay with her mother, Goldie, who lives illegally in a run-down house in London with Lyall and his son Robert. Cassie is persuaded to join the trio of artists and actors in rehearsing and performing a school presentation about wolves. One of the things Cassie's grandmother gave her when she left was a ball of strange, yellow substance similar to plasticine. Much of the book's theme revolves around the relationship of this yellow ball to Cassie's father, who is no longer around and who nobody wants to mention. The reason for this secretiveness becomes clear as the story unfolds, and the man's behaviour turns out strangely reminiscent of a wild animal fighting for survival. As the plot develops, readers learn a lot about wolves and their links to human beings. Cross wants to show how misunderstood and unfairly maligned they have been over the centuries. They are not fierce and horrible, but brave and smart. The author is also very clever in the way she combines people's irrational fear of wolves with the real modern fear of terrorism. Even though most people live buildings and houses in towns and cities, rather than under the trees in deep, dark forests, we still face real threats that frighten us and perhaps give us nightmares. Readers can identify with Cassie's feelings through her dreams, described briefly in each chapter. Her night-time images all relate to elements of the fairy tale Little Red Riding Hood. Fairy tales were originally written to help people confront their fears. Cassie deals with hers as the story reaches a gripping climax. Cross is a talented writer who has won many awards, and this book was the deserving winner of the prestigious Carnegie Medal.