The Subtle Knife recap

Will Parry, a boy from an Oxford like ours who has secretly cared for his ill mother, kills an intruder hunting his missing father's papers and flees through a hidden window into Cittagazze, a city where soul-eating Spectres prey only on adults. There he meets Lyra, arrived from her own world, and the two children join forces, passing between worlds. Lyra befriends Mary Malone, a physicist whose Shadows are the same conscious Dust from Lyra's world. A schemer called Sir Charles Latrom, secretly Lord Boreal, steals Lyra's alethiometer and demands the subtle knife from the Tower of the Angels; Will wins the knife, losing two fingers, and becomes its bearer, able to cut between worlds. As witches and other powers gather for a coming war, the aeronaut Lee Scoresby seeks the shaman Grumman and dies protecting him. Grumman reveals himself as Will's father, John Parry, tells Will the knife is decisive, and is then killed. Will returns to find Lyra abducted by her own mother, and two rebel angels appear, offering to guide him to Lord Asriel.

In the first book, Lyra Belacqua, an orphan raised at Jordan College in a world where human souls take the form of animal daemons, was given a truth-telling alethiometer and drawn into a struggle over a mysterious substance called Dust. She exposed the charming Mrs. Coulter as a leader of child-stealers, journeyed north with the gyptians, befriended the armoured bear Iorek Byrnison and the aeronaut Lee Scoresby, and destroyed a station where children were being cut from their daemons. She learned that Lord Asriel and Mrs. Coulter are her father and mother. In the end Asriel killed Lyra's friend Roger to tear open a bridge between worlds, and Lyra, believing the Church wrong about Dust, crossed that bridge into another universe to seek the truth for herself.

In an Oxford much like our own, a boy named Will Parry, long the sole guardian of his troubled mother, kills a man who breaks in searching for his missing father's letters. Fleeing, he passes through a window hidden in the air into Cittagazze, a sunlit but strangely deserted city where invisible Spectres devour the souls of adults but leave children alone. There he meets Lyra, newly arrived from her own world, and her daemon Pantalaimon. Wary at first, the two children team up, moving between Cittagazze and Will's Oxford. Guided by her alethiometer, Lyra seeks out Mary Malone, a physicist studying the dark matter she calls Shadows, and realizes that Mary's particles are the same conscious Dust that has shaped her life. Witches from Lyra's world, led by Serafina Pekkala, gather and follow, while Will begins searching for the truth about his lost father.

A wealthy man in Will's Oxford, Sir Charles Latrom, reveals himself as Lord Boreal, a traveler from Lyra's world; he steals Lyra's alethiometer and demands, in exchange, a knife kept in the Tower of the Angels in Cittagazze. In the tower Will fights for the blade and, at the cost of two fingers, becomes the new bearer of the subtle knife, a weapon that can cut windows between worlds and slice through anything. The old guardian Giacomo Paradisi teaches him its powers and its strict rules. Using the knife, Will and Lyra break into Latrom's house and recover the alethiometer. Meanwhile the aeronaut Lee Scoresby, hoping to protect Lyra, sets out to find a knowledgeable shaman called Stanislaus Grumman, as witches and other powers begin to converge, aware that a great war is coming.

The knife draws every power toward it. Lee Scoresby finds the shaman Grumman, who understands that the blade is an ancient weapon, the key to the coming war between the forces of the Authority and those who would defy it, and that its bearer must be protected and guided. Witches ally themselves with the children's cause, though they do not all agree on what should be done. Will struggles to master the knife and its dangerous responsibilities, and he and Lyra are pulled deeper into events far larger than Will's search for his father. Enemies, including Lyra's mother, press closer, and the shaman turns all his effort toward reaching and aiding the knife's young bearer before the gathering armies collide.

Lee Scoresby makes a desperate last stand to buy the shaman time, and dies defending the pass. The shaman Grumman finally reaches Will and heals his wounded hand, then reveals that he is John Parry, Will's own lost father, and tells his son that the subtle knife makes him a crucial figure in the war to come. Moments later Parry is killed by a witch who had loved him and whom he had spurned. Grief-stricken at finding and losing his father at once, Will returns to camp to find Lyra gone, taken by Mrs. Coulter. Two rebel angels, Balthamos and Baruch, appear to Will and pledge to lead him to Lord Asriel, but Will refuses to go anywhere until he has found and freed Lyra.

The book closes with loss layered on loss. Lee Scoresby dies in a rearguard fight to protect the shaman Stanislaus Grumman. Grumman uses the last of his power to heal Will's maimed hand and then reveals the truth Will has sought his whole life: he is John Parry, Will's father, who vanished through a window years before and became a shaman in another world. He tells Will that the subtle knife he now bears is the most important weapon in the war beginning across the worlds, and that he must carry it to Lord Asriel. Almost at once, Parry is shot dead by a witch who once loved him and could not forgive his rejection, so that Will finds and loses his father within minutes. Returning to camp, Will discovers that Lyra has been drugged and carried off by Mrs. Coulter, her own mother, who wants her out of the Church's reach. As Will stands alone and desperate, two rebel angels, Balthamos and Baruch, reveal themselves and promise to lead him to Asriel's fortress. Will refuses to abandon Lyra, insisting that finding her must come first. The knife is his, his father is dead, and the war can no longer be avoided.