The Subtle Knife is the second book in the His Dark Materials trilogy. At the end of the first book Lord Asriel created a door between two worlds and Lyra followed him through it. In this book we learn that there are many other worlds and that there are doorways to some of them. We also meet Will, a boy of about Lyra’s age who lives in our world. By chance he finds a doorway to another world where he meets Lyra and their adventures begin.
In Northern Lights Lord Asriel claimed that he was opening a door between worlds so he could find the source of Dust and destroy it. Lyra followed him to try to stop him. In The Subtle Knife we learn that he really wants to wage war on the Authority, an angel who claimed supreme power eons ago. Will becomes the bearer of the subtle knife, a weapon that can cut through anything and can also cut doorways between worlds.
It’s hard for me to review The Subtle Knife without giving too much away, so I’ll just say that I found it a very satisfying sequel to Northern Lights. The idea of doorways between alternative worlds is intriguing and well handled. Pullman keeps the story moving along nicely, with a reasonable amount of danger and suspense. The books may have been written for children, but I thoroughly enjoyed them.