As the Germans invade Belgium 9 year old twins Jan and Marie experience the horrors of the First World War. Separated from their mother and father after a bombing raid, the children meet with much danger as they search for their missing parents. In the course of their search they assist a family of refugees, and are themselves sent as refugees out of the country before being reunited with their family.
In this sad hour of the world's history, when so many homes have been broken up, and so many hearts burdened with heavy sorrows, it is comforting to think of the many heroic souls who, throughout the struggle, have gone about their daily tasks with unfailing courage and cheerfulness, and by so doing have helped to carry the burdens of the world, and to sustain other hearts as heavy as their own.
It is comforting, also, to know that there are many instances of happy reunions after long and unspeakable anxieties, adventures, and trials.
This story of two little Belgian refugees is based upon the actual experience of two Belgian children, and the incident of the locket is quite true.
The characters of the eel-woman and the mother of the Twins have also their living originals, from whose courage and devotion the author has received much inspiration.