The Book of Dust
The Book of Dust by Philip Pullman will be a companion novel to His Dark Materials, focusing on the stories of the secondary characters of the trilogy, such as how the balloonist aeronaut Lee Scoresby met the armored bear Iorek Byrnison.
The novel is also expected to include a continuation of the story about Lyra that was started in Lyra's Oxford. Publication of The Book of Dust is expected sometime in 2005.