The Amber Spyglass recap

Mrs. Coulter hides the drugged Lyra in a cave to keep her from a Church that wants her killed, believing prophecy names her a second Eve. Will, bearing the subtle knife and helped by rebel angels and tiny Gallivespian spies, has the blade repaired by Iorek Byrnison and rescues her. Together they journey into the land of the dead to free the ghost of Lyra's dead friend Roger; leaving their daemons behind, they release all the ghosts to dissolve into the universe. Mary Malone, among the wheeled mulefa, builds a spyglass that reveals Dust draining from every world. In the great war, Will and Lyra free the ancient Authority, who crumbles away, while Lord Asriel and Mrs. Coulter sacrifice themselves to destroy the Regent Metatron. Reunited with their daemons, the two children fall in love, which halts the loss of Dust and settles their daemons into adult forms; an assassin priest is killed before he can harm Lyra. But because open windows drain Dust and breed Spectres, all must be closed, and Will and Lyra, unable to live in each other's worlds, part forever, promising to remember each other each year.

Across the first two books, Lyra Belacqua, raised at Jordan College in a world where souls take animal form as daemons, was drawn into a war over the conscious substance called Dust. She learned that Lord Asriel and Mrs. Coulter are her father and mother, destroyed a station where children were cut from their daemons, and crossed a bridge Asriel tore between worlds. In another world she met Will Parry, a boy from an Oxford like ours, who became bearer of the subtle knife, a blade that cuts windows between worlds. Together they were pursued by the Church and by powers beyond it. Will's long-lost father, recognized only at the moment of his death, told Will the knife was central to the coming war. At the end of the second book, Lyra was drugged and carried off by Mrs. Coulter, and two rebel angels offered to guide Will to Lord Asriel.

Mrs. Coulter hides the drugged, sleeping Lyra in a remote mountain cave, guarding her from a Church that has decided the girl must die, since prophecy names her a second Eve whose temptation could damn or save all worlds. A local girl, Ama, senses something wrong and tries to help wake her. Will, grieving his father, is joined by two rebel angels, Balthamos and Baruch, who mean to bring him to Lord Asriel, but Will insists on rescuing Lyra first. When his knife is broken, he seeks out the bear-king Iorek Byrnison to repair it. Meanwhile the Church's Consistorial Court, fearing the temptation above all else, grants a priest, Father Gomez, absolution for a murder not yet done and sends him to kill Lyra. In yet another world, the physicist Mary Malone passes through a window and begins to find her way among strange new surroundings.

With Iorek's help the subtle knife is mended, and Will, aided by the angels and by two tiny Gallivespian spies, Tialys and Salmakia, reaches the cave and rescues Lyra from her mother. Reunited, the two children fix on a daring, secret purpose: to travel into the world of the dead. Mary Malone, in the world of the mulefa, wheeled creatures who live in balance with the Dust they call sraf, learns their ways and builds an amber spyglass through which Dust becomes visible. Through it she makes a disturbing discovery: Dust is steadily draining out of the worlds, a loss that threatens conscious life everywhere. As Lord Asriel's rebellion gathers strength and the Church hunts Lyra, the children prepare for a journey no living person is meant to make.

To reach the land of the dead, Lyra and Will must do the unthinkable: leave their daemons behind at the shore, an agony that feels like tearing away part of themselves. Accompanied by the loyal Gallivespians, they cross into a grey underworld where the ghosts of everyone who ever died linger under the torment of harpies. There Lyra finds the ghost of her friend Roger, whose death she has never forgiven herself for, and keeps her promise to come for him. In the mulefa world, Mary continues her study of Dust and of the great trees whose life depends on it. Across the worlds, Lord Asriel's forces and the armies of the Kingdom of Heaven move toward open war, and Father Gomez keeps relentlessly to Lyra's trail.

Lyra strikes a bargain with the harpies: in exchange for true stories, they will guide the dead. Will cuts a window out of the land of the dead into the living world, and the ghosts stream out to dissolve joyfully into the physical universe, freed at last from their grey imprisonment. Emerging, Will and Lyra are caught up in the vast battle between Lord Asriel's republic and the forces of the Authority. Amid the chaos they come upon a crystal litter holding the Authority himself, the first and oldest angel, now unimaginably frail; when they gently free him, he simply dissolves away into the wind. The Regent Metatron, who rules the Kingdom in the Authority's place, turns the full force of his power against Asriel's rebellion.

Mrs. Coulter goes to Metatron pretending to betray Asriel, and together she and Lord Asriel spring their trap: they seize the Regent and drag him, and themselves, over the edge of a bottomless abyss, destroying Metatron at the cost of both their lives. The war for the worlds turns on that sacrifice. Will and Lyra, still parted from their daemons and worn to exhaustion, search for a way back to the world of the living and to their souls, while Father Gomez, still hunting, closes in on Lyra with murder in mind. Mary Malone, in the mulefa world, senses that a turning point is near and prepares, without knowing it, to play the part the Dust has chosen for her.

Reunited with their daemons, Will and Lyra come to the mulefa world and to Mary Malone, who tells Lyra the story of how she lost her faith and found love. As Lyra and Will realize they love each other, the drifting Dust stops draining and begins to settle again around them, and their daemons at last take fixed adult forms. The angel Balthamos kills Father Gomez before he can shoot Lyra. But joy turns to grief: they learn that every window cut between worlds leaks Dust and breeds soul-eating Spectres, and so all of them must be closed, save the one that lets the dead escape. Because no one can live long in a world not their own, Will and Lyra must return to their separate worlds and never meet again. Heartbroken, they part, vowing to sit each year on the same day on a bench in the Botanic Garden of their own Oxford. Lyra, who has lost her instinctive gift for reading the alethiometer, resolves to grow up and help build the Republic of Heaven in the world where she belongs.

The war ends through sacrifice: Lord Asriel and Mrs. Coulter together drag the Regent Metatron into a bottomless abyss, dying to destroy him, while the ancient Authority, freed from his crystal litter by Will and Lyra, simply dissolves into the air. Reunited with the daemons they left at the shore of the dead, Will and Lyra reach the world of the mulefa and Mary Malone. There, as Mary tells of losing her faith and choosing love, the two children fall in love themselves. That love fulfills the prophecy: the Dust that had been draining out of all the worlds stops flowing away and begins to settle again, and their daemons take their final adult shapes, Pantalaimon a pine marten and Will's daemon a cat. The angel Balthamos kills Father Gomez before he can murder Lyra. But they learn a hard truth: every window the knife has cut leaks Dust and spawns Spectres, so all must be closed except the one through which the dead escape. Because a person can only truly live in their own world, Will and Lyra must return to their separate worlds and can never meet again. They part in grief, vowing to sit each year on the same day on a bench in the Botanic Garden of their own Oxford. Lyra, her instinctive gift for reading the alethiometer gone, resolves to grow up, study, and help build the Republic of Heaven where she belongs.