Into this wild abyss,

The womb of nature and perhaps her grave,

Of neither sea, nor shore, nor air, nor fire,

But all these in their pregnant causes mixed

Confusedly, and which thus must ever fight,

Unless the almighty maker them ordain

His dark materials to create more worlds,

Into this wild abyss the wary fiend

Stood on the brink of hell and looked a while,

Pondering his voyage . . . 

—John Milton, Paradise Lost, Book II

The Golden Compass forms the first part of a story in three volumes. The first volume is set in a universe like ours, but different in many ways. The second volume is set in the universe we know. The third volume will move between the universes.