This was sitting on the library shelves and it was by the author of The Hunger Games, which I loved and favorably reviewed, so it seemed like it might make for an interesting read. If I had known it was part of 'The Underland Chronicles' I would never have picked it up. I make it a policy never to read anything with the word 'chronicles' (or 'cycle' or 'saga') associated with it, but once again the idiot publishers failed to put a warning on the cover that this was part of a series, much less a chronic one! Personally I think they ought to have a warning affixed similar to that one attached to packs of cigarettes, worded o the effect that it was written by an unimaginative, or washed-up, or outright lazy author who can't do original work anymore, but that's just me.
I began listening to it before I knew any of this. It was poorly read by Paul Boehmer and the story was poorly written for my taste, so I quickly gave up on it. It was too young for me. According to Wikipedia, the story begins thus: "Eleven-year-old Gregor is left home alone in his family's New York City apartment to watch his sisters and grandmother. When Gregor's baby sister Boots falls through an old air duct grate in the building's basement, he dives in after her. The two fall miles below into the Underland: a subterranean world home to humans with near-translucent skin; giant sentient bats, rodents, and insects; and an escalating conflict between the human city of Regalia and the rats' King Gorger."
So maybe this will appeal to a younger audience, but based on my admittedly limited experience, I cannot commend it.