"It was time to whip the god," opens John Scalzi's The God Engines. I immediately went pale. Remembering that the first chapter of The Android's Dream was one extended fart joke, all I could think was, Please, no, don't let this be a masturbation scene. Nothing doing. Very little of Scalzi's trademark humor is in evidence in this story, a startling fantasy/horror/space opera mashup that may well be the bleakest and most violent thing he's ever written. Scalzi has never been a writer to take bold, running leaps out of his comfort zone. Instead, he's evolved at a calm and unhurried pace, making incremental changes in his storytelling approach each time. His Old Man's War novels have gradually shifted from Heinlein-inspired space opera, to reflections on the nature of humanity and identity, to young-adult coming-of-age adventure. And they've done it so organically that each novel feels distinctly Scalzi, and all of a piece, despite having pretty different thematic concerns.

But a very different Scalzi has written The God Engines. So different, in fact, that I suspect what really happened was that John's evil twin Spike chewed through his ropes, emerged from the crawlspace, disabled John with an impressive series of hapkido moves rated 8/9/9.5 respectively by John's cats, and then left the poor man bound and gagged in an amusing position in the garage while writing the story and cackling to himself. I'd like to think that, because it's one of those things where reality is probably less fun.

The story is actually a novella, published as an elaborately illustrated stand-alone hardcover by Subterranean Press. (And one look at its production values pretty much tells you all you need to know about the aesthetic inadequacies of ebooks.) Its future is one in which gods, who may or may not be highly advanced extraterrestrials, have a complex relationship to spacefaring humans. The Bishopry Militant is the body that appears to govern all human culture throughout inhabited space, and they in turn serve their One True Lord. This Lord has no name because he needs none. When your god is at the top of the divine food chain, names just get in the way.

There are other gods, but they have been beaten, vanquished, enslaved by the One True. The story's title is literal: these lesser deities serve as the actual engines of the Bishopry's spaceships, using their inexplicable powers to propel the vessels across vast gulfs of space. They do this very much under duress.

Ean Tephe is captain of the Righteous. The ship's high priest, whose acolytes help control their captive god, is Croj Andso. They've been having a harder time keeping control lately. Despite being chained, the god has brutally attacked at least one hapless acolyte. Word is out that similar rebellious behavior has been happening among the gods aboard other ships. Something is afoot. Tephe is summoned to the Bishopry, where he is told that the True Lord's followers have insufficiently strong faith, and it's making the enslaved gods bolder. Here Scalzi puts a clever spin on a theme explored in such novels as Neil Gaiman's American Gods and Terry Pratchett's Small Gods. Gods only last as long as they have true believers. Just as lesser gods serve as the engines of the Bishopry's spaceships, faith serves as the engine that keeps the One True Lord in power. (An interesting thing is the way the characters define faith. As they have proof positive that their deities exist, you'd think faith would be superfluous. But they don't understand how the gods do what they do, hence "faith" is basically defined as knowledge without understanding.) But inherited faith, that which is taught from generation to generation, is never as strong as the fiery fanaticism of the fresh convert. It just so happens there's somewhere in the universe to find this kind of faith. The Lord has planned for this necessity. Pretty clever, but then, he is a god.

Going darker doesn't work seamlessly for Scalzi. The story feels a little stuffy, even pretentious, in some of its early chapters. Fantasy dialogue is usually bad when it sounds like Fantasy Dialogue™, and The God Engines doesn't avoid that trap. Characters don't sound like they're speaking so much as declaiming. Backstory is conveyed this way, turning everyone into an exposition-happy windbag who doesn't use contractions. The effect is to rob characters of depth, as everyone says exactly what's on their minds.

But the plot is a well-oiled machine, and at just over 130 brisk pages, it does its work efficiently and doesn't overstay its welcome. In its surprising final third, when assumptions are overturned, beliefs are challenged, and our heroes' sense of what's right and wrong in the universe is thrown into chaos, The God Engines shifts into high and redlines right across the finish. The climax is as visceral as anything Scalzi's ever done. Thematically, I suppose the story is open to being thought of as one interpretation of the idea of religions as memes, self-propagating viral systems that take more from their believers than they give. But I don't think that was really Scalzi's intent here. I think he just wanted to let his evil twin out to play. He should do it more often.