When Lyra's friend Roger disappears, she and her daemon, Pantalaimon, set out to find him. They travel to the ice kingdoms of the North, where armoured bears rule and witch-queens fly through frozen skies. Lyra possesses a device that will aid their quest - ifshe can decipher its mysterious messages. But it knows terrifyingsecrets about their journey, and the dangers that await them in worlds far beyond their own.