In Lyra's world, aëronaut Lee Scoresby learns that the explorer Stanislaus Grumman had become a shaman among the Svalbard tribes, and steals the ring of the Church from an agent.

Will is excited, because he has also found a window (into Cittàgazze), and knows what his father is talking about. From it he learns that John had found, on this expedition, a 'window' leading into another world, and had written the coordinates of the 'window' in one of his letters. Will examines a folder which contains his father's letters, which is what the men were searching for. Will visits a library, where he learns that his father, John Parry, went on an expedition into the Arctic, but never returned. The alethiometer informs Lyra that the alethiometer itself, Mary's computer, and the I-Ching are all elaborate methods of communicating with Dust/Shadows. Astonishingly, 'Shadows' are attracted to objects that are made by human beings more than to completely inanimate objects, and appear to be sentient in their own right. Lyra, guided by her alethiometer, seeks help from a physicist called Mary Malone, who studies dark matter via a computer that measures the level of the so-called 'Shadow particles' around certain objects. Little does she know that as she consults the alethiometer, she is being watched by Sir Charles Latrom, who is actually Lord Boreal. Lyra visits a museum, where she learns that humans began to attract an increased quantity of the mysterious substance called Dust approximately thirty-five thousand years before then.

Lyra and Will, searching for information, return to the Oxford of Will's world. Children (pre-adolescent) cannot see the Spectres adults can, making them vulnerable and therefore afraid to live in any city occupied by these predators. Lyra and Will learn that the city is called Ci' gazze (they later learn that this is an informal rendering and that the full name is Cittàgazze), and that it is haunted by thousands of beings called Spectres.

His dark materials the subtle knife