His Dark Materials

This is one of the supreme works of imaginative fiction for both children and adults published in the 20th century.

Northern Lights introduces Lyra, an orphan, who lives in a parallel universe in which science, theology and magic are entwined. Lyra's search for a kidnapped friend uncovers a sinister plot involving stolen children, and turns into a quest to understand a mysterious phenomenon called Dust. In The Subtle Knife she is joined on her journey by Will, a boy who possesses a knife that can cut windows between worlds.

As Lyra learns the truth about her parents and her prophesied destiny, the two young people are caught up in a war against celestial powers that ranges across many worlds and leads to a thrilling conclusion in The Amber Spyglass.