The premise is Nolan Garret is the assassin Cerberus. A former space marine called a Silverguard, he rids the galaxy of its worst scum for his employer. Unfortunately, Nolan is over a barrel as his brother is imprisoned for treason and his boss doesn't mind using that for leverage. Having uncovered his boss is involved in criminal dealings, he's decided to play it cool and continue to investigate while pretending to be a loyal employee. This sends him back to his homeworld, currently in a mining dispute between corporations, and causes him to face his past.
I like Nolan Garret as a protagonist and think he's always entertaining to read. He's a man fanatically devoted to the honor of the Silverguard, even when it's increasingly clear that not all of them hold the same degree of nobility that he ascribes to its members. He's also an assassin who makes ample use of technology as well as his wits to do some truly thrilling action scenes. He's a bit too noble but has enough flaws that it's still believable. I also like his relationship with his A.I. who provides a kind of sounding board for a lot of inner character development that wouldn't otherwise be possible.
This book has a strong contrast to the first one as instead of taking place in a densely packed urban cityscape, it goes to a rural mining community that isn't too far removed from the 20th century. The book takes on the features of a Neo-Western, really, with Nolan being the gunslinger who needs to protect the locals from the big bad newcomers that are polluting the area by extracting heavy metals. They have military grade weapons and a bunch of goons that our hero is going to have to go through one-by-one in order to stop it. Thankfully, this doesn't have to be done on his own time since his target as a government assassin is one of them.
Complicating this issue is the fact that Moabus is his hometown and it's full of uncomfortable relationships he's left behind like his ex-girlfriend Callie as well as school rival Gavin that is now part of the bad guy's mooks. He's also still suffering from the traumatic death of his parents in a car accident that he was part of. Enough of an event that he never wanted to return to Moabus again despite his lingering feelings for Callie. There's a lot of good action, mystery, adventure, and crazy sci-fi battle scenes through the book. Fans of progressive fiction will also note there's a trans character that Garret knew as a child growing up whose existence gets a, "Oh that's neat. Good for you" reaction.
Criticism-wise, I have to say I much preferred the gritty megacity setting of the first book. Moabus feels a little too normal and while farmers like Uncle Owen and Aunt Beru can exist in science fiction, it hurt the feel of the book I believe to have things so similar to present times. I will admit to finding humor that flannel and Daisy Dukes survive to the 41st century. I also feel the narrative made an excellent twist about something one of Garret's love interests did to him that was genuinely shocking, only to roll it back and reduce the impact of the event. Finally, there's a character named Hal that I very much liked but didn't think they got nearly enough screen-time.
In conclusion, I definitely am going to be picking up the second volume. If you like audiobooks, I also recommend picking up the Audible version as the narrator did a fantastic job.