So how many aspects of good writing can you hack out of a Big Fat Fantasy and still have something I’m willing to read through—or at least skim through—to the end? Thanks to Brandon Sanderson’s Mistborn trilogy, I now know the answer: almost all of them.

By any sane standard Mistborn is ninety percent pabulum. The prose is the written equivalent of an oatmeal-on-wonder-bread sandwich. The dialog is subtly unlike anything any human would actually say, but that’s understandable; the characters aren’t people so much as mannequins pushed around a chessboard by an army of tiny robots. The little narrative details that, in a good novel, give rise to its most memorable and vivid images are too ordinary to recall. There is humor—for a trilogy that builds to a total apocalypse, Mistborn is charmingly unwilling to sink into the kind of unrelieved bleakness that battered me into giving up on George R. R. Martin after four bloated books—but I only know it’s humor because, like a long-lost Wonder Twin, it takes the form of humor. None of it is funny.

Then there’s the underlying worldview, with which I have Issues. Most extruded fantasy products, modeling themselves as they do on pre-modern history, build worlds run by kings and queens. In a lot of these books, the key to defeating the Big Bad is in planting the right royal ass on the throne. If there’s no great supernatural evil to defeat, the whole book is all about cheering on The Man (or Woman) Who Would Be King. I’m not big on hereditary dictatorships in real life, so you’d think the fantasy feudalism would bother me. It doesn’t, because in most of these books monarchy is all anyone knows. It’s not fair to expect a cast of characters living in the equivalent of 12th-century France to come up with representative democracy—although if they did, that would be great.

Here’s the problem with Mistborn. Brandon Sanderson’s hero does come up with representative democracy. And backslides. Elend the scholarly policy wonk is a flop; Elend the third-world strongman, complete with crown and gleaming pseudo-military uniform, has the peasants swooning. It’s not until he and the heroine take over and start conquering cities that they get a grip on things. Mistborn is carefully crafted to need a strongman. It’s a fantasy trilogy written for an audience of Dick Cheney.

And yet: I read Mistborn. Faster and less closely than I read most books, but the whole damn thing. How? Why?

Brandon Sanderson has one thing going for him. He’s got plot. And worldbuilding, I guess. Mistborn’s world and plot are in symbiosis. Mistborn builds its world as meticulously as Agatha Christie built murders, and in a lot of ways it’s a mystery novel. Learning the world is the plot. As the trilogy begins the characters don’t know very much more about their world or its magic system (which seems designed mainly to allow the heroine to show off in a series of wuxia-influenced fights; if this thing is ever filmed it has got to be done in Hong Kong) than the readers. Every piece of plot has a place in the big puzzle. Every question has an answer. Every small, apparently incidental detail means something. It all builds to a climax that’s unexpected but makes perfect sense. Reading Mistborn is like watching a huge and useless but perfectly executed Rube Goldberg device do its thing.

So why did I finish Mistborn? For pretty much the same reason I finished all those Agatha Christie novels. And, like the Christies, I’m probably not going to read this one twice. The dominoes have fallen, and there’s no point sticking around to see them set up again.