In this stage of the adventure a new character is introduced, Will, who is a child from our world who passes over into another world. In that world he meets Lyra and they recognise that they need each other to survive. Lyra goes to Oxford in our world to find out more about Dust, and Will heads to the library to find out more about his father. Will is on the run from men who also want to find his father, and Will accidentally killed one of the men so the police are also after him.
Lyra befriends the academic she meets at Oxford and shows her what Dust can do, and gives her advice on how to extend her research. Lyra also encounters a man from her world whom she does not recognise until he has stolen the alethiometer. The man bargains with them and says that if they get the subtle knife for him, he will return the alethiometer.
A number of other events occur but basically there is going to be a war between good and evil, and the knife and Lyra are tied to the outcome. All the main characters in the story are on their way to Lord Asriel to join the fight.
This book starts off really slow as Will is introduced as a main character and Pullman needs to explain who he is to the audience. I really missed Iorek Byrnison in this book but Pullman writes another action packed novel full of adventure and from about halfway through the book there is too much going on to worry about Iorek.
Part 2 of His Dark Materials deepens the relationships formed in Part 1 - and the audience understands how much the adults Lyra encountered in Part 1 care for her and are willing to risk their lives to ensure her survival and success. Some of the questions from Book 1 are answered, but more questions are asked to be answered in the final book which I am hurrying to read now.