TWO BOOKS DOWN!
The City Spies are a group of teens and pre-teens, chosen for their super abilities in areas such as computer hacking, code breaking, and pickpocketing. Almost more important that their skills are that they are orphans with no family so that they can go undercover and not leave a trail. They live together with their spy mastermind guardians until their help is needed to (come on, you knew this was coming) SAVE THE WORLD. Meanwhile, one of their guardians has a secret which he needs their help in solving.
So, like all the fun thrillers out there, this series has all the great elements. However, the author has a fun lighthearted writing style which makes the reading enjoyable. I highly recommend this series if you are looking for fun reads for your preteen readers and/or yourself.