His Dark Materials. The Golden Compass ; The Subtle Knife ; The Amber Spyglass

In his award-winning fantasy trilogy, His dark materials, Philip Pullman invents a richly detailed and marvelously imagined world that is complex and throught-provoking enough to enthrall readers of all ages. The Golden Compass introduces us to an orphan named Lyra 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. The epic story Pullman tells is not only a spellbinding adventure featuring armored polar bears, magical devices, witches, and daemons, it is also an audacious and profound reimagining of Milton's Paradise Lost.
An utterly entrancing blend of metaphysical speculation and bravura storytelling, His dark materials is a monumental and enduring achievement.