Bob Cook and the German Spy

After the nation declares war, two patriotic teenage boys too young to enlist notice suspicious activity around their family's factory, which has taken a government contract to produce munitions. With help from local authorities and their own daring, they investigate rumored saboteurs, infiltrate deserted houses, uncover secret schemes, face mistaken identities, fires, and night raids, and collaborate in trapping agents, exposing a spy ring and protecting the community's war work; the story emphasizes youthful initiative, civic duty, and wartime vigilance.