If it has been a while since you have read Scorpion, I highly suggest going back to re-read it and remember the intricacies of who people are to each other. This book begins where the last one left off, still told from Kendras's point of view. This story is less action and much more political intrigue than the last. And this is to be a trilogy, so the ending is unfinished. It's a bit of a cliffhanger, even. (Though we can deduce what will happen next.) 
 So, when I originally read this story, I had reservations about Kendras becoming the Officer because I wasn't sure he could see Adrastes as anything but his Officer and make his own decisions, and that setup was completely intentional by the author. That problem becomes the point of this entire story - how Adrastes and Kendras change. Can Adrastes adjust to no longer being the Officer of the Scorpions? Can Kendras truly become the Officer? Can Kendras ever come to understand the level of politics--the chess match--he's being dragged into? Will the Scorpions stay or leave Adrastes? 
 The story begins with Adrastes and the Scorpions riding into the city of Dalman, where an attempt is made on Adrastes's life right off the bat. Adrastes and Kendras are still in something of a honeymoon phase with each other, but responsibility begins to weigh on Kendras. He knows that Adrastes plans to attempt to reunite the three cities and rebuild the Empire of Shara, with a legion of Scorpions leading the charge, but their unit is reduced to three. (Four if you count Kiran the tanesh, five if you count Selvan, their slave, too.) But that means Kendras must find new recruits. And if they become an actual legion, as Adrastes desires, then the brotherhood and ways of the Scorpions (as a mercenary group) will be lost to the mechanics of the military. Kendras makes more than one decision which goes against everything he knows about the history and Memory of the Scorpions, and he struggles with figuring out whether or not those decisions are right. 
 But what grates on Kendras the most is Adrastes forgetting it is the Officer who leads the Scorpions and that he no longer has the right to give them orders. Kendras watches as Adrastes changes from the Officer and comrade he has long known into not just a noble, but a King with a vision to become Emperor, standing on the backs of others to do it. The ideals which Adrastes once held become secondary to claiming that vision, no matter the cost involved. Adrastes doesn't even see it happening to himself; he forgets who Kendras is, his core self, and doesn't see that what he's commanding of Kendras goes against that nature that Adrastes once praised. 
 And we, as readers, know it is going to happen, that the two of them are going to fall apart when their worlds and ideals collide, because there is no other way for it to happen. But having to watch it happen through Kendras's eyes and share in that pain is difficult. We experience his wavering loyalty as Kendras watches Adrastes change right before his eyes, barely able to believe that the man in front of him was once the Officer he knew and trusted with his life. Kendras has some tough choices to make, and we watch as he grows into the person able to make those choices, pushed by Adrastes overstepping his bounds. 
 We also watch as Kendras grows apart from Adrastes and closer to another whose ideals more closely match those of the brotherhood of Scorpions he has grown up with. This felt entirely natural given the whole situation that Kendras is in, caught between a rock and a hard place. It is the strength of this relationship which grounds him, and maybe even helps give him conviction. 
 Additionally, the Jaishani enter the scene and stir things up. The Jaishani ambassador shows up for the coronation but sticks around for the aftermath to discuss strategy and assist in some ways. They drag Kendras further into the deceptions and lies because he is full-blooded Jaishani. 
 The pieces are intricately and expertly woven together. I cannot wait for the end of the story. 
 (And because I know he tends to read my reviews: Aleks, get right on that, please.) ;)