The Subtle Knife

Lyra and Pan have stepped into a world that feels oddly empty until they meet Will, a mysterious boy who seems to have no daemon but who quickly proves himself to be a worthy ally in Lyra's search for the dangerous substance called dust. Together this unlikely pair discovers a deadly secret: a knife that can cut the fabric between worlds. Many others want the knife as well, and so Lyra and Will find themselves chased from world to world, never suspecting how tightly their stories are bound together, until they are violently split apart.