Kate Elliott’s The Witch Roads opens with a deputy courier and her nephew having nearly completed her way along her monthly circuit through the outlying villages surrounding their home of Orledder Halt. Wanting to show her nephew Kem an unusual sight, Elen takes him to camp overnight in the mysterious towers nearby—where she gets more than she perhaps bargained for. The spirit of one of the guardian statues which line the narrow path to the stronghold seemingly comes to life and talks to her, demanding to borrow her body for an unspecified task. A day later, in an attempt to forestall the total collapse of the life she’s built in Orledder Halt, Elen volunteers to lead a high-ranking imperial prince and his party along a hidden overland trail to reach their destination in a matter of weeks instead of months. The spirit—which she calls a haunt, despite him insisting he’s no such thing—promptly takes over the prince’s body instead.

Luckily for everyone, the prince and the spirit both want to go to the limits of the Tranquil Empire, which is bounded by an offshoot of the impenetrable, plague-bearing Pall. Unluckily for Elen, she must somehow lead the expedition while covering for the spirit-as-the-prince and his total ignorance of everything the prince knows, all while trying to manage her relationships with the prince’s closest servitors. These include Kem, who has deftly played his own cards in order to become an apprentice Warden in the prince’s retinue, and is thus also along for the ride.

There’s a lot more plot and worldbuilding stuffed into The Witch Roads. I would certainly expect no less from a Kate Elliott novel, but The Witch Roads may be her most concise and economical book yet. It is the first half of a duology—the second book, The Nameless Land, is expected later this year—and it elegantly sets up and explores both a complex culture (actually two complex cultures, but we’ll get to that) and the ramifications of its sociopolitical system, particularly in terms of how the Empire has been impacted by the rise of the deadly Pall. This plague looks like a low-lying fog in its most advanced form, but it starts as spores; one of Elen’s duties as a deputy courier is to keep her eyes peeled for Spore, the Pall’s seeds, at all times, to forestall more widespread outbreaks. Because the Pall settles semi-permanently on the areas it infects, with only the so-called witch roads and the Halts they embrace as a guarantee against it, settlement and society in the Empire takes place in the Pall’s shadow. But the Empire itself may be starting to rot from within: Orledder Halt is fairly isolated, and the fairness with which it is governed stands in stark contrast to other parts of the Empire. That is demonstrated when the abusive lord who sired Kem arrives in town not only to brand Elen a murderer but to demand that Kem be acknowledged as his daughter, rather than the man Kem has already legally declared himself to be.

The Tranquil Empire is a queer- and trans-friendly society: Queer relationships are legal and socially acceptable; individuals are free to declare themselves to be another gender at age fifteen, as long as they acknowledge and take up their obligations to the Emperor (who can be a prince of any gender) at age seventeen. Lineage nevertheless matters: Kem is able to use his newly discovered aristocratic birth to escape his terrible father and swear himself to the career he wanted, but that career would have been closed to him as a commoner. For her part, Elen struggles to advise him, because she’s not running from one secret past but from two: She and her sworn sister, Kem’s dead mother Aoving, weren’t even from the Empire at all, but from the nameless land on the other side of the farthest Pall.

In the way that a good novel challenges its protagonist, Elen’s journey with the prince-haunt and his Wardens relentlessly bears her back toward the past that she has tried to put behind her, while her struggles to repair her relationship with her beloved nephew force her to tell him the truth of what occurred when she and Aoving first crossed into the Empire. The Empire’s paramount concern, her story shows, is not justice, but stability: Everything Aoving suffered in their first residence there was legal.

There are yet more plot threads I’ve barely touched on, including the question of who is trying to maneuver the prince into a politically untenable spot and what the prince knows about the nameless land, as well as what the haunt’s real mission is and how his existence connects (or doesn’t) to the Pall—and what the Pall even is, as well as whether it can ever be cured or driven back. Some of these questions are raised through Elen’s deepening relationship with the haunt, a mutual connection that they both feel but which their respective positions prevent them from indulging; some will hopefully be answered in The Nameless Land, which promises to further explore the oppressive, less complex society from which Elen and her sister escaped. The politics of the present, the mysteries of the Pall, and the secrets of the ancient past that birthed the haunt and the witch roads taken together give the world of the Empire a textured, lived-in feel. The rich cultures that Elliott depicts, as well as the fine gradations of etiquette and behavior that separate people across their ranks and classes, are wholly believable.

At the heart of the book, though, are Elen and Kem, and the shadow of his lost mother which lies between them. Elen was the practical, level-headed sister who stood in her sibling’s social shadow but devoted her life to making sure that her sister and her nephew were safe—a focus that she turned solely on Kem after Aoving’s death in an avalanche. But Kem is growing up and finding his own place, pushing at the boundaries of their relationship as all teenagers must, and Elen now finds herself unmoored. What will she do and who will she become, within the constraints of the Empire? Is there some unforeseen way for her and the haunt to find happiness? And how could that be, since he doesn’t even have his own body? Relentlessly pragmatic, Elen knows the Empire’s truths and its limits as only someone who wasn’t born to them can. But she’s human, and the heart can’t help wanting more. That Elen confronts these choices and painful desires in her mid- to late thirties, as a fully formed adult with plenty of life already lived, makes her an unusual and compelling fantasy protagonist.

If epic fantasy is about the scale of the story, then in The Witch Roads Elliott has written what may be the best epic fantasy I’ve read in years. Dense but never overwhelming, compact but never too brief, richly detailed and imaginatively constructed, queer-inclusive and sensitive to the ways in which society masks and justifies injustices along other lines, this novel makes a thrilling read out of what is at heart a long, difficult hike through the mountains. The Witch Roads may be Kate Elliott’s best single book. It’s an engrossing, thrilling story, with vivid characters to root for and recognize, and I hope we see many more stories in the Tranquil Empire beyond The Nameless Land.