The nitty-gritty: A complex world full of fascinating characters, Nightwatch on the Hinterlands is an excellent start to a new science fiction series.

I was so excited when this book was announced, a story set in K. Eason’s Rory Thorne universe but far in the future with different characters. And wow, was this a lot of fun! Nightwatch on the Hinterlands takes many of the world-building ideas I loved in Rory Thorne and expands on them even more. This is a very tech-heavy, tightly focused story that falls on the “hard” science fiction side of the spectrum, which doesn’t always work for me. But Eason tempers the technical elements with fascinating world-building, carefully developed characters and plenty of high stakes action, all of which made this a blast to read.

The story is set on the remote planet of Tanis and follows several main characters. Lieutenant Iari is a tenju templar, born and orphaned during the Expansion War. Iari joined the templars in order to fight, but now that the war is over, her job is to stop the Brood, the deadly monsters that appeared after the vakari inadvertently created a rip in the void called the Weep. The other main character is Gaer, a vakar ambassador who has been sent to the planet to work with Iari, but who in fact is acting as a spy and is secretly sending critical information back to his people.

Iari and Gaer have an uneasy relationship, but when the body of a murdered wichu is discovered, and when witnesses claim that a riev was responsible for the murder, Iari knows something isn’t right. Riev, the giant robot-like creatures that were created during the war to kill the vakari, haven’t been able to kill anything since the war ended, and why would one kill a wichu anyway? Wichu are a peaceful race who use magical arithmancy to repair broken riev, so the reasons behind the murder are a big mystery.

Iari takes a chance and decides to question a group of riev in the area where the murder took place, and is shocked to discover a much deeper and disturbing mystery: someone has figured out a way to reprogram riev to kill. With the help of two riev called Char and Brisk Array, Iari and Gaer start investigating the murder, but someone doesn't want them to find out the truth.

Readers who love complex worlds will adore this book, and the world-building was by far my favorite part of the story, closely followed by my love of the characters. And do note, if you haven’t read the Rory Thorne books, you can easily start here. Eason imagines a multiverse set far in the future where a mysterious rip in the universe—called the Weep—was accidentally created with magic during the war. The Weep allows a terrible breed of monsters to come through called Brood. There are different types of Brood, like boneless and swarm, and wow were they terrifying! The scenes where Iari and her friends are trying to kill them reminded me of the bone-numbing terror I felt when I watched Alien for the first time. 

Then there are the riev, whose original purpose is gone—the war is over and the vakari are no longer the enemy. Char was one of my favorite characters, and I loved the way Eason delves into the moral issues of robots and sentience. Riev were linked together by the Oversight, a network that gave them a hive mind, so to speak. But the Oversight is no longer in use, and a funny thing is happening: Char starts using the “I” pronoun, suggesting that riev are becoming individual entities. I loved seeing Char and Brisk Array develop their personalities over the course of the story, and the fact that Iari has a soft spot for the riev made me like her even more.

I also loved the wichu, tiny artificers who love to surround themselves with bright colors. The wichu started out as the enemy during the war, but defected over to the side of the Confederation. I pictured them as Munchkins from the Wizard of Oz, although I’m not sure if that’s what the author was going for!

In fact, most of the characters in this story aren’t human. Instead, we have Iari, who is tenju, a rather large humanoid race with tusks, and Gaer, a vakar who is skilled in arithmancy and reading auras. Iari is a devout templar, a religious group whose members are also fierce fighters. Iari has been exposed to fighting her entire life, raised as a war orphan and later as a templar. She’s had a needle socket surgically installed at the base of her skull which monitors her vital signs and communicates with her battle rig during a fight, a highly specialized suit of armor that not only protects the wearer but gives them super strength and speed. Iari takes her job seriously and shakes off injury in order to keep fighting, but she’s sometimes rash and jumps into the middle of the action without thinking things through.

I loved Gaer’s character as well. The vakari were enemies of the Confederation until only recently, so he’s still treated with suspicion. I loved his ability to read auras, which is rather intrusive, sort of like reading someone’s mind. There are some funny scenes where he can see Iari’s emotions—the ones she’s trying to hide—but reading auras also comes in handy because Gaer can tell whether or not someone is lying. Gaer is also adept at arithmancy, the ability to see and create magical mathematical equations called hexes, which we were first introduced to in the Rory Thorne series. In Eason’s world, mathematics is used to shape reality, and the multiverse depends on math to keep it in order. This unusual combination of magic and science is one of my favorite elements in the book, and I especially loved that Gaer, whose race is still feared by some people, is one of the most talented arithmancers in the story.

A third main character—another tenju named Corso—appears around the 25% mark in the story and joins in the search for the killer. Corso is an old war buddy of Iari’s, and they appear to have some history, but he wasn’t in the story enough for me to really get a feel for him.

As for the plot, it’s a fairly simple murder mystery. But what makes this story so complex are all the world-building details and the relationships between the characters. Because there are so many different alien races sharing space, the dynamics among them can get very tense. I especially loved the relationship between Iari and Gaer, which isn’t a romantic one, by the way, although I can see the author going there eventually. Gaer becomes very protective of Iari, and she does not like that at all. I wouldn’t call this story humorous, but there are some very funny scenes between the two, mostly because they are both fighters and Iari doesn’t want anyone seeing her weaknesses.

The mystery itself is complicated by the fact that certain species aren’t acting in the normal way, and so the reader slowly begins to understand how they interact with each other: tenju and vakari, tenju and wichu, riev and wichu, riev and vakari. The Brood is their common enemy, so they all end up working together to stop the Brood from swarming. Add in a bunch of political intrigue, which I haven’t even touched on in this review, and you have a dynamic story full of unpredictable characters.

The only negative I wanted to mention relates to the author’s narrative style, which tripped me up a bit. In the Rory Thorne books, the story is being told by an unknown narrator who often chimes in with his or her own opinions about what’s happening. It was a little jarring at times and took some time to get used to. In Nightwatch, we mostly bounce back and forth between Iari’s and Gaer’s points of view, and they often insert odd mannerisms into their speech that make it seem like they’re breaking the fourth wall and talking directly to the reader. Eventually I grew to love this quirky style, but some readers might struggle with it.

The stakes become higher and higher as the story progresses, with all of the characters in mortal danger at one time or another. By the end of the story, Eason has neatly set up the next book in the series but at the same time satisfactorily resolved all the big plot points. I can hardly wait to read the follow-up! Highly recommended.

Big thanks to the publisher for providing a review copy.