Britain, 1941.
The third in the pre-CHERUB series, not suitable for younger readers..
They are parachuted into unknown territory on a daredevil exercise in which they will have to outsmart a bunch of adults and fight for their lives.
The government is building a Secret Army of intelligence agents to work undercover, including a group of kids cut adrift by the war and who, for official purposes, do not exist.
Britain, 1941