It's funny that Rick Riordan is the only guy with a blurb on the outside of the book because I can see exactly how this fits into the "you secretly were born to go to hero school" genre that might appeal to Percy Jackson fans. And, you know, it was fine.
Lerangis's strength, in general, is a talent for great pacing and keeping action/adventure plotlines alive, and that is the main reason I kind of liked this book. I was never bored reading this—it's the kind of thing you can sit down with and be drawn in, losing time in the outside world because everything is happening with such fluidity and speed in the fictional world. And if I were twelve or thirteen, I can definitely see this as being a book I loved because it is just that exciting!
But for all the strength of the storytelling itself, my feelings about everything else are on the wishy-washy side of things.
For one thing, what was going on? I'll grant that there's a possibility I was reading too fast to get the things I should have gotten, but I just had a difficult time buying anything that was going on. With the bulk of the book taking place on a remote island and only four "Select" characters, our protagonist included, it was hard to relate the lost civilization from Atlantis with anything concrete in the world. I never felt totally sure why the kids had to receive drug treatments, I was not really convinced regarding the ancient Atlantis civilization, and I didn't understand why their "demigod" status was important to the world at large. If it weren't for the griffin at the end, I feel like you could make a compelling argument that the kids were basically hallucinating the whole time (while being fed lies from the institution) and it would be a valid reading of the text.
That said, overall the worldbuilding felt a little shaky. We never got the rules about what it means to be one of the Select kids, why they die at age fourteen, their significance to the world. I got that they were responding to situations that began in Atlantis times, and yet I also didn't really understand why their institute was at war with the monks. It was just... vague. Again, maybe I'm missing something, but for me not to know their Capital-P-Purpose at the end of the book is concerning.
(But it's the first book in the series, imaginary haters in my brain say. More would be explained in the next books. I know, I reply. But it's the first book so it's supposed to be the one doing the heavy lifting for the rest of it, dangit.)
I've been using "the Select" as a shorthand for the four main characters (Jack, Marco, Cass, and Aly), but while we're here, I do not like "the Select" as a thing, at all. Maybe because it reminds me of the Calvinist elect, or something. Bhegad, the institute's head, explicitly describes the kids' condition as a "survival of the fittest" situation, made special because they carry the blood of kings (55). The Loculi, the things they are supposed to be getting, only respond to that same "royal blood," which gives this whole book an air of genetic superiority that I didn't like and am not going to.
Beyond that, I wasn't really into the characters themselves. Marco was a token black kid; Aly was a token girl. Cass seemed like he had compulsive behaviors, but they dominated his character to the point that we only saw his interiority one or two times. Aly was a love interest for Jack; there were zero sparks. It's a book that seeks to achieve a "found family" narrative, but I never felt a sense of belonging between the characters. (I do think a multi-POV storytelling device would have helped on some level.)
There are some other things I could comment on—unproductive escapes, magical healing, the fact that ancient civilizations are referred to modern country names (9.9), and the fact that I had no idea whether I was supposed to care about Marco at the end—but there is one thing that really bugged me and we are going to talk about it.
Professor Bhegad and the Karai Institute were ridiculous and I couldn't take the story seriously when they were in play, and that's the whole truth. These two things had two poles, where one end was "incompetent and morally bankrupt" and the other side was "idealistic and sympathetic" and there was no in between. Bhegad (a man of color, btw) would say things like "hacking is an ugly word" even though he'd literally sanctioned hacking or give children illegal drugs against their wills, and so you'd think he's probably evil (55). But THEN he would seem to be intelligent or nice or just trying to help and he'd kind of actually mean it and so he was kind of supposed to be a "good guy" all along???
Bhegad in particular felt far more inconsistent than complex, and the fact that nobody ever got around to making an official statement as to the Karai Institute's actual evilness made me frustrated and disappointed.
So.
TL;DR: You know, I thought I liked this book more than I did, but while it was good writing, at the end of the day the concept bothered me too much to like it, which is a shame.