His Dark Materials 3: The Amber Spyglass (Junior Edition)

Will is the bearer of the subtle knife. He has promised his dying father that he will deliver the terrible blade to Lord Asriel. War is coming, the greatest war there has ever been, and the knife is the only weapon that can defeat the enemy. A stranger in a world that is not his own, Will sets out on a perilous journey. But how can he fulfil his promise when Lyra, his brave companion, has disappeared...?