Book one of the series Recon Team Angel
Humanity is losing the war against its alien invaders. Earth has been almost entirely conquered, with the Americas as the only free territories still under human rule. This could be humanity's last chance to strike back. A team of six has been chosen to infiltrate the enemy's headquarters in the heart of the Australian Outback.
The six teens have been modified to look like aliens. They have spent years mastering alien culture so that they can talk, act, even think like their enemies. But from the start, the recon mission goes terribly wrong. It's only when they are close to discovering the shocking truth of the aliens' plans that the team is forced to ask: Who amongst them is a traitor?