Northern Lights

Scholastic, 1998. Minor shelf wear and creasing to spine, pages yellowing at edges.

Book 1 in the Dark Materials Trilogy.
When Lyra's friend Roger disappears, she and her daemon, Pantalaimon, determine to find him. The ensuing quest leads them to the bleak splendour of the North, where armoured bears rule the ice and witch-queens fly through the frozen skies - and where a team of scientists is conducting experiments too horrible to be spoken about.