What is Un Lun Dun?

It is London through the looking glass, an urban Wonderland of strange delights where all the lost and broken things of London end up . . . and some of its lost and broken people, too–including Brokkenbroll, boss of the broken umbrellas; Obaday Fing, a tailor whose head is an enormous pin-cushion, and an empty milk carton called Curdle. Un Lun Dun is a place where words are alive, a jungle lurks behind the door of an ordinary house, carnivorous giraffes stalk the streets, and a dark cloud dreams of burning the world. It is a city awaiting its hero, whose coming was prophesied long ago, set down for all time in the pages of a talking book.

When twelve-year-old Zanna and her friend Deeba find a secret entrance leading out of London and into this strange city, it seems that the ancient prophecy is coming true at last. But then things begin to go shockingly wrong.