The second book of Philip Pullman's epic fantasy trilogy brings Lyra and her daemon and a cast of characters both familiar and new into whole new worlds. Lyra and 12-year-old Will Parry, in a desperate flight for his life, are drawn closer to Will's father and closer to the Subtle Knife, a deadly, magical, ancient tool that cuts windows between worlds. Through it all, the pair are drawn deeper and deeper into a fierce battle that they may not survive.