Received via NetGalley for review.

An exciting middle-grade novel for those who like that particular genre of kids-fighting-kids/monsters (which I do, and which lots of people do!)

I wish there had been a little more room for character development - there are a lot of characters, and a lot of action to get through (I definitely thought Eric, Marcus and Spex were going to have a larger role, and three of the four girls are basically interchangeable).

But the action is fun and dangerous, and exactly what I was looking for. I'm always a sucker for the trope where people are chosen for a specific reason, and I was glad Finch called Cade out on that but just as glad he got to use his knowledge to succeed.

It's a little hard to believe that a small group (8?) of teenagers, many of them with vastly different perspectives, would manage to defeat hundreds of monsters where entire legions of Roman soldiers before them could not (though maybe the Roman soldiers were further along in the competition before they all failed? But then why would Cade and his group start off in the beginning?), which I hope will be addressed in the inevitable sequel but probably won't be. ( )

This is the kind of book I'd love to have written. It has boatloads of suspense, a terrifically creepy world, unusual characters and lots of action. Best of all, while the first in a trilogy, it very much satisfies at the end, leaving this reader very excited for what will come next. ( )