Camp X: Shell Shocked
Book 4 of 6 in the series
By Eric Walters

Jack and George have assumed new identities and are back at work as special operatives, keeping an eye out for suspicious activity at an ammunitions plant. They don't have to wait long before they uncover a plot by German spies to blow up the plant and everyone in it! It's up to the quick-thinking boys to find a way to stop them and stay alive while doing it ...