London schoolgirl Hettie hears the whispers and sees the worry creeping across her parents' faces. She watches as the windows in her home are blacked out. She helps her dad build a bomb shelter. She learns how to wear a gas mask. War, led by Adolf Hitler, is stomping its feet at Great Britain's doorstep, and Hettie knows only one thing for certain: When the bombs come, it will take all the courage she has to be brave and survive.