You can bet when I saw the words “gender-swapped Alexander the Great in space” used to describe a book, my immediate reaction was PUT IT IN MY EYEBALLS. Plus, it’s written by Kate Elliot, who wrote the totally amazing and ass-kicking Spiritwalker fantasy trilogy. I figured Unconquerable Sun was a guaranteed winner.

Folks, it is a winner–eventually. After a stuttering start, it is jam-packed with incredibly cool and interesting sci-fi world-building and nonstop twisty politics and action. Also, there are space dinosaurs.

Most of the book centers around the exploits of Princess Sun, a bold and daring twenty-year-old princess who is itching to get involved in the military exploits of her martial homeland, the Republic of Chaonia. Sun and her Companions (essentially advisors and hostages from the other major noble families of the Republic) are embroiled first in internal political intrigue and then in an attempted invasion that threatens the entire Republic. They have to turn the tides in favor of their homeland against numerous obstacles, sometimes including Sun’s own mother, the haughty and somewhat complacent Queen Eirene. It is a classic underdog space opera story.

Though she is her mother’s only heir, complicating Sun’s position within the Republic is her ethnic background; she is half-Gatoi and her father is a Gatoi prince who is not trusted by the Chaonian nobility. (The Gatoi are essentially supersoldier space nomads who feature heavily in the twists and turns of the plot).

There are so many truly amazing and unique pieces of worldbuilding in Unconquerable Sun that it’s worth reading for that alone. I don’t think I can do justice to all of the ideas here and how seamlessly interwoven they are into the fabric of the plot. In terms of the overall vibe, the universe of this book reads like an avant-garde giant robot space anime, Star Wars, and an ancient epic poem had a baby.

For example, most fast interstellar travel takes place through “beacons” that allow for near-instantaneous travel between two fixed points. The beacons are ancient technology from a collapsed ancient space empire. When the ancient empire collapsed, so did some of the beacons, essentially leaving certain planetary systems “stranded” in space. People alive in the book’s present understand enough to maintain and use the beacons but nothing more, and passing through the beacons is described in almost spiritual terms. As one of the main characters, Persephone, relates:

I fell in love with the beacon network the first time I went through a beacon transition, many years ago. Not everyone sees it, because I’ve asked.

But I see it.

I see the ghost of the network deep in the heart of a black nothingness that is transition. Faint traceries like infinitesimal gleaming arteries shimmer in a void. Ships like droplets of water slide along whatever passages beacons rate between each other.

The combination of the technological and mystical is ever-present in this universe and it is one of my favorite things about the book. Frankly, even the idea of a human-occupied space in which space empires so old they are ancient exist is mind-blowing. The oldest known historical spacefaring civilization in the book’s universe, the Celestial Empire, is old enough that it is considered quasi-legendary. The scope of the world here is frankly awe-inspiring.

While the world-building is expansive, most of the plot is closely focused on several points of action. The majority of this book is a series of tightly executed chases and battles of varying scales, from small-boat escapes to interplanetary spaceship battles with hundreds of ships. The action remains fresh and exciting throughout. I found the combination of the highly textured world with the constant running and shooting and flying and sneaking to be quite successful.

However! Even though the world-building and plot were strong and engaging eventually, I found the first 20% or so of the book to be a real slog. Because this is a VERY long book, 20% is a long time to be semi-bored while reading. Like, over-one-hour bored. In fact, if I had not been reviewing the book, I might have quit. I’m glad I stuck it out, but it is something a reader should definitely be prepared for.

The initial section of the book drags for two reasons. First, there is a lot of inelegant info-dumping. This includes several particularly painful early conversations between Sun and her father, Sun and her mother, and Sun and her bodyguard, Octavian, that simply scream “These Conversations Only Exists to Inform You, The Reader, Who the Major Players in Space Are.” Think older adults pulling up maps of space and directing Sun to describe what she sees, e.g. to declaim information that is surely obvious to all of the characters. This felt clunky for me, as the reader. It’s not fun to read an account of someone else basically taking a pop quiz. I think pretty much all of the information presented this way could have been inferred from context, and indeed, that is why the world-building is so good otherwise.

The other reason I struggled through the first part of the book is that it felt overly heavy on set-up. It almost felt as though the book started too early, as the main plot action does not really take off until about the 16-17% mark. I think the entire first 20% of the book could have been reduced by two-thirds without losing anything essential to understanding the subsequent events.

Other than the boring initial segment, my other main criticism of this book is its uneven characterization. While some characters are dynamic, complex, and exciting, others seem fairly wooden and undifferentiated.

I think part of this is a point-of-view issue. There are two major POVs for the majority of the book (with some additional POV guest stars). The first major POV is Sun. When we follow Sun’s POV, the book is in third person, and while we do sometimes get to hear her thoughts, I would say it’s not a particularly close third person perspective. This creates a sense of distance and renders Sun a somewhat opaque character. She is still moderately compelling; the complexity of her relationships with her parents coupled with her own ambition for Chaonia is fodder for intriguing characterization. However, the sense of distance makes it hard to appreciate her as a protagonist. Here’s a brief excerpt of how to prose reads when we are following Sun:

Sun tilted her head to get another angle on the object: small, probably no bigger than a thumb, and coated with a nonreflective surface to make it hard to see. She inhaled and exhaled fully, inhaled again as her fingers wrapped around the rifle and exhaled until her shoulders relaxed. On a held breath she sat bolt upright as she swung the rifle up to sight level and released a pulse.

With a snap and a burst of light, the object tumbled out of the sky to vanish into the water. Everyone deck swiveled their heads to look.

She jumped to her feet. ‘Did anyone see where it went in?’

It was hard not to feel that sometimes the narrative voice here bordered on clinical.

The other major POV is that of Persephone Lee, the runaway daughter of a noble Chaonian house who gets re-embroiled in Chaonian intrigues and becomes a Companion to Sun. Persephone’s POV is in first-person. This turns Persephone into a much more accessible and thus significantly more engaging character. Perhaps because Persephone’s voice feels so much more immediate, flawed, and human, the characters who primarily orbit around Persephone were much more interesting for me as a reader than the characters primarily connected to Sun. Here’s an excerpt from Persephone’s perspective:

‘Rise and shine, Cadet Lĭ,’ says the silky voice I once mistook for sincerity. I turn to see Cadet Jade Kim leaning against our lockers with arms crossed and a smug half smile. ‘I think you want to talk to me and not that junkyard hatchling.’

Solomon is out of his bunk and up in Kim’s face so fast I don’t have time to think up a retort.

‘You want to repeat that?’ Solomon asks in his softest tone. He’s half a head taller than Cadet Kim and maybe twice as broad across the shoulders, not that Jade Kim isn’t also a well-built specimen of youth, which is how I foolishly leaped into the pit of that relationship in the first place.

Persephone’s casual self-deprecation and more vivid focus on emotion and implicit interpersonal dynamics made me much prefer her POV.

While I was mostly engaged and swept along by the action while reading regardless of the perspective, I was occasionally struck by the strangeness of reading a book where I was highly invested in some of the primary characters and I felt basically nothing for others.

I also want to advise any romance readers intrigued by the mention of Sun’s “secret lover” in the book’s blurb to temper their excitement. I found this aspect of the book to be among the weakest and Sun’s aforementioned lover to be totally bland and uncompelling. The only positive thing I have to say about it is that it is an F/F relationship in a world where queerness is a nonissue. With that said, there is also another, much more satisfying small romantic subplot that I really enjoyed, so I did still get some of the romance I was looking for from this book.

Overall, Unconquerable Sun gets a gazillion mega cool space points from me for the sheer breadth and imagination of the world-building and the fun, twisty, action-y plot. It loses points for a boring start and some issues with presenting consistently compelling characters. I think fans of the sci-fi genre should pick this up just to check out all of the fascinating elements of the Unconquerable Sun universe. If you are not already interested either in sci-fi, or you are turned off by the idea of highly action-driven plots at the expense of characterization, it might not be worth it for you to try to slog through the dry beginning.