Gregor the Overlander, Suzanne Collins

Okay, so I have a new favourite fifth grade boy fantasy series obsession.  (I know, you're shocked.)

If you are one of those people who believes that there must be a colony of gargantuan rats and cockroaches living under the streets of New York City, consider yourself vindicated. When Gregor's baby sister crawls into an air vent in the basement of their apartment building, he follows her down a long dark chute and into the Underland.  Fortunately, they are found by the friendly giant cockroaches and not the evil rats.  The cockroaches bring them to the city of the Underland humans.  There Gregor learns that his father who disappeared two years earlier fell down the same chute and ended up prisoner of the rats and that Gregor himself may be the warrior hero mentioned in an ancient Underland prophecy.  Together with the snobby young queen and her insufferable cousin, two loyal bats, two kind cockroaches, and the snarky, bitter traitor rat Ripred (my personal favourite character!), Gregor sets off on a quest to save the Underland human race from destruction. 

The book is dark but awesome and ultimately has a pacifist message, which is interesting for a fantasy questing book.  I'm so excited to read the rest of the series!