The Subtle Knife, by Philip Pullman (on CD)

This series is so clever it's hard to find anything bad to say about it. This book does suffer from Book-Two-of-Three Syndrome, to the extent that the climax is rather...uhm...hard to spot. Unless the whole book is the climax.

It also introduces a huge new chunk of cast while almost or completely, ignoring many of the characters in the first book (one can hope that some will return in Book 3). The only American character, I'm sorry to say, appears here but most likely won't be around much later.

So, new people: Will, a boy Lyra's age from "our" world, and also a physics professor at Oxford named Mary Malone. The major 'character' in the story, however, is the world of Cittàgazze (which means "City of the Magpies"--which gives a lot away, but only if you know Italian, no?), where Will and Lyra meet and discover that their futures are intertwined and inseparable. They soon find that to forward their own quest (Will is looking for his father), each must help with the other's quest because it's all rolled up together: there is a huge war coming, a war between Good and Evil, between Death and Life, between Knowledge and Ignorance. The universe will either be reborn or die.

Creepy Mrs. Coulter is in this book, too, but not as much. There are some wonderful scenes: Lyra tasting Coca-Cola for the first time, Will's ability--like the witches--to disappear at will, the concept of the knife.... Oh, the knife, which can cut through anything at all, including the curtains between all the billions of worlds in the universe. It's a wonderful, terrible knife, and it exacts a price of its Bearer.

This is YA fiction? Yes.