Volume in the John Marsden Presents Australian Children's Classics series, in which the bestselling writer for young adults selects and introduces classic Australian books for children. Marsden provides a foreword for each title in the series. Originally published in 1940, this title was originally part of the 15-volume Billabong series. Australia is on the brink of war and four young people have to prevent a secret enemy attack. Author (1878-1958) was a journalist at the 'Age', where she ran the children's page on the 'Leader'. The Billabong series began with 'A Little Bush Maid'.