Lyra, the protagonist of Northern Lights and The Subtle Knife, is held prisonner by her mother, the ambitious and ruthless Mrs Coulter who also drugged her to ensure her docility. When her companion Will delivers her with the help of the angels names Balthamos and Baruch, Lyra reveals that their next task is even more dangerous and hopeless that anything they survived until now: they have to enter the land of the dead...