This review is for the entirety of The Underland Chronicles. No spoilers. 
 If you liked The Hunger Games, this is a must read. Many similar themes are explored, like the effects of war and violence on young people, government corruption, losing loved ones, the value of peace and cooperation, and of course young love. Clearly issues close to Suzanne's heart, and no less skillfully explored here. 
 But this is a very different world. Politics play a heavy role in this story and each species has a very different culture. The bats (aka fliers) and the humans (aptly named the killers) are extremely close allies, along with the mice (nibblers) and the cockroaches (crawlers). But the spiders (spinners) try to balance and be neutral, and most of the rats (gnawers) want all the humans dead. The moles (diggers), we find out later, also pretty much despise humans. It's very complicated on the surface, but it maintains a feeling of realism and makes great sense in the context of the story. It's so well-built, in fact, I have a little theory the author might have actually fallen down a hole in Central Park. 
 Pepper into this fascinating world characters with personalities and motivations just as varied as the cultures they come from: the gnawer Ripred, the crawler Temp, the flier Ares, just to name a few favorites, and you have a place I really want to live. There are no distinct villains, no definite evil. When Gregor first arrives he sees the rats as completely bad and makes quick friends among the humans, but he learns quickly that the species does not dictate the personality. In war there is always good and evil on both sides. 
 Much like her other work, these books are filled with suspenseful action scenes of graphic fights and battles, and yet they manage to be remarkably anti-violence. She manages to use the most reviled creatures of our world - rats, cockroaches, bats, spiders - to demonstrate the perils of racism and prejudice. By the end of the first book, I was in love with Ares, Temp, and Ripred (though he is an acquired taste). In real life all of them would give most people the creeps. And the fact that she names the humans the killers shows us just what she aims to illustrate. 
 But as Suzanne is wont to do, once you fall in love she will inevitably put your favorite characters in the most dangerous situations, from which any safe return would be unbelievable. She maintains the realism to the last, and spares no punches when it comes to death. So brace yourself. 
 Finally let me come to the one "con" I have with this story, which may be a tiny spoiler if you're nitpicky. This has long been a sticking point with me and this kind of "two world" style fantasy. In The Wizard of Oz, or Alice in Wonderland, the main character visits a fantastic world apart from our own, which from all appearances is just... better. But repeatedly throughout, they just want to go home. 
 In New York, Gregor is a poor kid with a tiny closet for a bedroom, always stressed about having food to eat and clothes to wear, struggling to help raise his two sisters and sick grandmother. In the Underland, he is the Warrior, a hero to an entire underground city of humans, none of whom are ever hungry or mistreated. He has two friends in New York. In the Underland, he has more friends than he can count in multiple species who would give their lives for him, and he for them. 
 If it were just to get back to his family, I would understand. Of course Dorothy wanted to go back to her aunt and uncle. But even when Gregor's family is in the Underland, and they all make their own friends and it's obvious they could have a life there, he still wants to leave and go back to his tiny apartment in New York. WHY?! 
 It is for this reason, and this reason only, that I cannot give this series a 10. That "Why?" is a question I never got an answer to, even at the very end. So I am left wanting, with unfinished business you might say. Nevermind that the romance had just gotten started when she ended the books! 
 I can only hope Suzanne will write another book about Gregor that can tie this up for me!