This is the first book in the Dark Materials triology by Phillip Pullman. The main charatcer is Lyra with her daemon Pantailamon. Her best friend called Roger disappears and she goes on a quest to find him, but she find out alot more than she bargins for and with many twists, she ends up on the island of Svallbard watching the northern lights.
I would highly reccomend this book, and i suggest that after you read this book, you read the other two in the trilogy, The Subtle Knife and The Amber Spy Glass, each as brilliant as each other
There is also a film comnig out about this book in the near future