Lyra Belacqua is the main protagonist of Pullman's trilogy. She is headstrong and impulsive but ultimately a bright and courageous girl with a deep capacity for love. Raised in a relatively unsupervised fashion at Jordan College in her world's Oxford, Lyra eventually learns she is the illegitimate daughter of Lord Asriel and Mrs. Marisa Coulter. Lyra is pulled into the conflict between her parents and the groups they represent. Lyra has the unique ability to communicate with Dust, a substance with which both groups are obsessed, through a truth-telling device called the alethiometer. She is also important because a prophecy has indicated that she will be the "new Eve," whose actions will determine the future of humankind. In The Subtle Knife and the Amber Spyglass, Lyra continues the journey to her destiny along with Will Parry, the bearer of the subtle knife. Eventually Lyra does fulfill her role as the second Eve, passing from girlhood to womanhood when she falls in love with Will. Their transition to adulthood and their budding sexuality stop the Dust from flowing out of their worlds, saving humankind from more years of oppression by the Church.
Will Parry is a brave 12-year-old from our own world, introduced to readers in The Subtle Knife. Will has had to protect and care for his mother since his explorer father disappeared seven years before. After killing a man who comes to his house looking for something of his father's, Will discovers a strange window that leads into another world. There he meets Lyra and becomes her companion, protector, and best friend. Responsible, cautious, and courageous, Will is a born warrior with a fierceness that makes even adults fear to look him in the eye. In Cittàgazze, a world beyond the Northern Lights, Will also learns that he is the next bearer of the subtle knife, a tool that can cut the fabric between worlds. His ability to wield the knife makes him the focus of a hunt by the Magisterium, Lord Asriel, and all the warriors aligning themselves in the battle of the heavens. Along with Lyra he helps free untold millions of ghosts from the world of the dead, where they were imprisoned by the Authority. He also helps stop the disappearance of Dust and more years of oppression by the Church when his relationship with Lyra leads to adult experience and a sexual awakening. He is the Adam to her new Eve.
When readers are first introduced to Lord Asriel in The Golden Compass, it is through Lyra's eyes. She knows only that he is involved in "high politics, in secret exploration, in distant warfare," and that he is her uncle. Only later does she learn he is her father and is planning a rebellion against the Church and its god, the Authority. Asriel sees the Church as both oppressive and tyrannical and believes Church leaders sanction unspeakable acts in the name of religion. He plans to replace the Authority's corrupt kingdom with his own democratic Republic of Heaven and is also seeking the source of Dust, which he believes is the cause of all the death and evil in the world. To achieve his goals, Asriel builds a device that will open a portal between his world and the world from which he believes Dust emanates, and he even sacrifices the child Roger to provide the energy that is required. His actions turn his daughter, Lyra, against him, but Asriel later realizes the best way to achieve his goals is to allow his daughter to fulfill her destiny as the second Eve. He sacrifices himself in a battle with Metatron, the Authority's regent, in order to save his daughter. As an idealistic, morally problematic rebel, he stands in for the Satan of Paradise Lost.
Mrs. Marisa Coulter
Mrs. Marisa Coulter is beautiful, brilliant, and heartless. She is also Lyra Belacqua's mother, having had the child after an illicit affair with Lord Asriel. Fiercely ambitious, she seeks power by convincing the Magisterium to allow her to investigate Dust, which they believe corrupts children when they reach puberty. To achieve her goals, she sets up the Oblation Board, which abducts children and sacrifices them in experiments where they are severed from their daemons, which is fatally dangerous. After Lyra herself becomes a target of the Magisterium, however, Mrs. Coulter has a change of heart and joins Lord Asriel's rebellion against the Church and the Authority. Eventually she sacrifices her own life in a battle with Metatron, regent to the Authority, in order to save Lyra's life.
Mary Malone was once a nun in "our" world but gave up her vocation when she realized she preferred to live life more fully, and after she decided Christianity was "a very powerful and convincing mistake." In her research Mary became aware of what she called shadow particles, the Dust of Lyra Belacqua's world. When Lyra is directed to Mary by the alethiometer, they combine what they know and realize that not only is Dust conscious but also they can communicate with it. Before they can explore discoveries much more, Lyra is forced to flee, and Mary is directed by the Dust to go after her through one of the windows between worlds. Mary enters the world of the mulefa, where she learns more about Dust and realizes it is disappearing from all worlds. Unknown to Mary, she will have a role in stopping the loss of Dust by playing "tempter" to Lyra's Eve and showing her the path to adulthood and sexual awakening. When she, Lyra, and Will are eventually brought together, Mary tells them about the paradise of love and the children recognize their deep love for each other. When they do the flow of Dust slows.
Lee Scoresby, a good friend of Iorek Byrnison, begins in a mercenary role—he's been hired by the gyptians to escort Lyra—but when she is abducted, he goes in search of Stanislaus Grumman whom he believes has an object that can protect Lyra. After finding Grumman, who is actually Will's father, John Parry, he sacrifices himself so that Parry can continue on his mission to find and deliver the subtle knife. Later, as a ghost, he saves Lyra from Father MacPhail's bomb and then continues to fight on, joining Lord Asriel's army in the final battle against the Authority. Scoresby's dream while he is alive is to settle down to a private life as a farmer—"nothing grand," he says.