World's End represents a sort-of sequel to Vinge's Snow Queen. Taking place after the events of the earlier novel, we follow one of the characters from that book, BZ Gundhalinu, as he tries to move on with his life.
Gundhalinu left Tiamat through the stargate at the end of the previous story, separating himself from Moon Dawntreader Summer for all time. He returns to his police work, but remains haunted by his earlier experiences. When he learns that his two older brothers have squandered the family fortune and then disappeared into the World's End region of the resource-rich planet Number Four, Gundhalinu follows them. Many people travel into World's End, seeking their fortunes, but few return. Gundhalinu makes the trip partially out of a sense of familial obligation, and partially as a way of distracting his unsettled mind.
World's End is quite a bit shorter than its predecessor; it's almost a novella. That length proves deceptive however, as the book packs quite a lot into its narrow binding. On the surface, the book plays as the story of Gundhalinu's journey, the chapters laid out as days in a journal. This tale carries hints of Heart of Darkness or The Treasure of the Sierra Madre in its DNA. But there is also a mystery element, as Gundhalinu gets tasked with finding the eerie Fire Lake and a missing sybil named Song (in addition to this brothers) and must use his police training to unravel clues to what is happening in World's End. Meanwhile, Vinge plumbs the depths of Gundalinhi's mental state, taking us deep into his guilt and shame. So we are faced with a psychological thriller, detective story, character study, and science fiction novel, all wrapped into one.
Despite all of those components, the book feels tight and crisp. The only section that seems to drag a little comes about two thirds of the way in when Gundhalinu descends into madness. But given the importance and necessity of that plot element to the tale, I had no complaints.
I was surprised by how different this book was from The Snow Queen and also by how much I really liked this dark little tale. Sequels to popular or well-known stories are hard to do effectively. Authors are prone to duplicate the previous book, or to go so far afield that the original audience is alienated. Judging by the reviews here on Goodreads, World's End probably veered too far toward the latter approach for some readers. Nevertheless, I found it an intriguing, original, and satisfying novel in its own right.
One caveat: Like its predecessor, this is not a book for children, despite its origins in a fairy tale. Vinge's depictions of sex, violence, and mental illness are adult material.