The Assault Chisnall, the commander of the Angel Squad, is deployed with his crew, ready to fight the alien invaders. His team has been specially designed for the mission; they sport the alien's looks and most of the alien's traits. As his team infiltrates the base, they have a traitor on their hands. Chisnall tries to find the traitor, hoping that the mission isn't completely failed because of him/her. When Chisnall's crew gets into the base a few aliens are suspicious that they aren't really aliens. The squad fights their way out when the aliens discover who they really are. This instigates the final war between the aliens and the humans.
This book had a lot of funny moments, but it was more action than anything. I think that the author could have used more detail in describing the aliens. You never would have realized that the squad had been transformed into an exact replica of the aliens. I think overall, this was a great book. I just generally think that many kids would love this series.