Snake Agent is a marvelous blend of science fiction, fantasy, and horror, a very different book with an intricate, solid plot. I don't know why someone didn't tell me about Liz Williams before now.
Actually, I've had this book for over a year, languishing in my To Be Read pile because of its thickness (I'm not fond of very long books) and the unattractive cover. I picked it up mostly because I'd been looking for a meaty urban fantasy but couldn't find one. This was far better than anything I had expected.
Detective Inspector Chen is an investigator of the supernatural as part of his job in the Singapore Three police department. When a woman asks for help finding the soul of her murdered daughter, who should have arrived in heaven but instead ended up in hell, Chen starts an investigation that uncovers a conspiracy between corrupt humans and one of hell's most powerful ministries. At the same time, Seneschal Zhu Irzh, a demon in hell's Ministry of Vice, is sent to investigate the appearance in hell of innocent souls--young women who were supposed to go to heaven but ended up in the brothels of hell without the proper paperwork.
This would be only slightly interesting to me if the heaven and hell were those from the Judeo-Christian mythos. Instead, the setting is a mixture of Chinese legend and science fiction/fantasy invention. It's fresh and exciting, endlessly fascinating. There's much more to the book than the main plot, too. Chen's wife has an important role--so much so that I'm afraid to say anything about it for fear of spoiling something.
Liz Williams handles viewpoint shifts with a masterful touch--ordinarily I really hate books with multiple points of view (which is such a bugbear with me that I actually try not to let it influence my reviews), but it worked so well in this book that I barely noticed.
The writing is descriptive and lovely, the characterization deft. Williams is able to define a fully realized character with one perfect line of dialogue. And the worldbuilding is astounding. In fact, in terms of characterization and worldbuilding, I'd rank Williams right up with Sarah Monette and Scott Lynch. Like both those authors, her writing is layered and nuanced without becoming unwieldy. I have no idea why she isn't more popular--or maybe she is and I'm just the last person on earth to read her.