The Golden Compass by Philip Pullman

The book follows the journey of a young girl in a parallel universe where people's souls exist outside of their bodies as animal companions, called daemons. When her friend is kidnapped by a mysterious organization, she sets off on a quest to rescue him, armed with a truth-telling device known as the golden compass. Along the way, she encounters a variety of characters, including witches, armored bears, and aeronauts, and uncovers a sinister plot involving the children of her world.

The 739th greatest book of all time