It's back to the days of bubblegum rationing and blackouts, and we find Zoe, aged 10, her younger sister Rosie and their friend Joe Bunch sitting out the war in a sleepy midwestern town. When collecting old tin cans and newspapers begins to be a bore, the trio sets out to do some real ""war work"" and forms a Looking-for-Spies-Club. Zoe, a self-admitted coward, is appalled when some real clues begin turning up, and her assignment as a spy involves taking tap dance lessons from Miss Lillian Lavatier, the prime suspect. Still, it's mostly the momentum of Joe's patriotism and Zoe's capacity for dramatization (she makes up newspaper headlines about their operations) which keeps the spy ring going until Zoe finds herself trapped in the Lavatier cellar, surrounded by mysterious cartons, and is warned to keep her mouth shut or ""the whole thing will blow up on us."" The ending is a really explosive surprise (for everyone but Joe who knew it all along), and the 1940's ambience has been lovingly recreated.