If you have a reader in 4th through 8th grade, you have probably seen the Maximum Ride series by James Patterson. The story follows Max (AKA Maximum Ride) and her "flock" of genetically altered friends as they attempt to save the world from a pharmaceutical-military company out to destroy it.
The stories are a mishmash of Third Reich meets X Men meets enviromental propaganda meets kid power action. The writing is weak, at best and the character development nonexistent. There is no nuance, no shading. Adults are almost uniformly bad, and have destroyed the world.
Still, the books move along at a clip and are certainly engaging, in the way candy corn is: it's great until your teeth hurt and then it's too late.
For an almost equally far fetched scenario but with better writing and character development, go for the Alex Rider series by Anthony Horowitz.