Thanks to my great friend Ethel for sending an engrossing trilogy, just when I needed one. I'm on the third book...wonderful reading for all ages and anyone who needs to sit still, relax and get away for awhile.
The funny thing is that my first impression of this story is that the author, Philip Pullman, made it up as he went along, which he seems to deny in the first question under FAQ on his website. But many of the characters, threads and details do not carry through the story and it really seems that he is more faithful to his imagination than to plot or character consistency...but you be the judge.
Q: Did you have the whole story in your head when you began writing His Dark Materials?
A: Yes, in outline, though not in detail. I haven't got enough RAM in my head to deal with 1300 pages of yet-unwritten material. But any writer of stories has to have a certain architectural sense, I mean a feeling for large shapes, and an instinct for whether they'll stand up safely, or need lots of propping up to make them steady, or whether they'll just fall down whatever you do, and so on. And of course when you begin a large project like His Dark Materials, you make sure beforehand that the large shape is secure.
It's the details you can take chances with, and afford to be surprised by. I don't like planning things too tightly, because then you're not surprised by anything. I was very surprised by the armoured bear, Iorek Byrnison, for example; I hadn't expected him to be a bit like that. And the Gallivespians in The Amber Spyglass surprised me enormously.