The Subtle Knife (Chudesny Nozh)

A sequel to the book 'Northern Lights.' After the events on Svalbard, Lyra Belacqua finds herself in a new world where she meets Will. Will is twelve years old and has just committed murder. Together, they find themselves in a city of abandoned children called Chitagazza, where the streets of earth are roamed by Ghosts who devour the souls of adults but fear children, and the sky is shared between witches and snow-white angels. Each follows their own path: Lyra seeks the meaning of Dust, and Will his missing father, but they discover an object of great power—the Enchanted Knife, capable of cutting through anything, even windows to other worlds.