The Amber Spyglass brings Philip Pullman's His Dark Materials trilogy to a resounding conclusion.

Lord Asriel is massing his armies for his battle with Heaven, and two lesser angels, Balthemos and Baruch, approach Will Parry. They want him to deliver the subtle knife to Lord Asriel, but Will wants to find Lyra, who has been abducted from where she slept. The angels reluctantly agree to accompany him, and with the help of Iorek Byrnison, the king of the armored bears, he finds where she is being held in a drugged sleep.

Will isn't the only person looking for Lyra. Agents of the Church are also looking for her; believing that she is prophesied to bring about the downfall of the world as they know it, they send an assassin after her, a priest who has done "pre-emptive penance." He has a long way to go to find her, however, because she and Will have undertaken a chilling and dangerous quest -- they have gone to the land of the dead.

Lyra wants to find her friend Roger's ghost and apologize for leading him to his death and to help him in any way she can. Accompanied by Will and two Gallivespians, tiny people who ride specially engineered fireflies and who often work as spies, she makes her way to the land of the dead, only to find that to complete her quest requires a terrible sacrifice.

At the same time, Dr. Mary Malone has also traveled through the window between the worlds. She finds herself in a world populated by mulefa, intelligent quadrupeds who help Mary make some important connections between Dust and the environments of all the worlds. Mary also builds the amber spyglass of the title which allows her to see and study the Dust, which the mulefa call sraf and which she calls dark matter.

The battle for Heaven continues, pitting Lord Asriel and the rebel angels and allies against the Authority -- the first angel who then presumed himself Creator -- and the Authority's Regent, Metatron, a strong and brutal angel determined to institute total control over humanity through offices of the Church. The enigmatic Mrs. Coulter also plays a crucial role in the battle, but in the end, it is up to Lyra to make a choice to decide the outcome, although it is a choice that will require another enormous sacrifice.

Pullman sustains the momentum of the first two books with a complex and multi-layered story which is impossible to put down, even though the novel is just over 500 pages. His writing is vivid; the scenes come easily to live in the reader's imagination. The characters are equally complex and thus well-rounded, and their actions, reactions and emotions are authentic. Furthermore, the book can be read on a number of levels, making it suitable for any age reader and is sure to inspire debate and discussion about the philosophical and theological ideas presented. At the same time, the power of the story is not overwhelmed by the subtext.

With The Amber Spyglass and the other books of the trilogy, The Golden Compass and The Subtle Knife, Philip Pullman has created that rare and wonderful thing: a modern classic that will live on through generations.