Good series starter
This is a very good series introduction.
From the critical side, my first impression was that Rachel Carter broke one of the cardinal rules of naming lead characters--using one that could be hard to pronounce. "Ryiah" doesn't flow from the tongue. Perhaps it is just me, but I still don't know how to say it. The phrase "you guessed it" also made me cringe when it appeared outside a quotation, as I think she tried a bit too hard write like a 15 year old girl. I also would have liked to have seen more character development from the final grouping of successful individuals. It seemed that they were just names picked out of a hat at the end, with only one exception. However, it was only these relatively minor points and a few grammatical errors that kept this from getting a full five stars.
The plot is excellent, even if somewhat transparently obvious. Carter does a masterful job of creating a love-hate relationship and fostering the confusion between the two young leads. The dramatic effects of the grueling, life-altering pressure applied by their schooling is palpable. One can't help cheer on the accomplishments as they occur. The reader can also feel the tension develop right from the outset, and the increasing waves of ebb and flow add to the credibility of the ending.
The secondary plot line between Alex and Ella also works spectacularly, as both of the characters change just enough that their final exchange makes perfect sense.
The pacing flows perfectly, and I really couldn't put it down once I got to the last two chapters.
We learn enough of the worldview to get an introduction to the series, and because the only thing outside of "normal" pre-gunpowder earth is a bit of magic, Carter doesn't need to waste a lot of words setting the stage. I am sure we will learn about Jerar's history in subsequent novels, but more isn't needed in this introduction.
In summary, if you are looking for a quick-reading Young-Adult novel with just the right mix of conflict, teenage angst, arduous training and magic, go ahead and grab this one! Very likely you will be asking soon for book two!