It describes the experiences of the American airmen who participated in the Normandy invasion during World War II. The book was published in 1944, just a few months after the invasion, and it provides a firsthand account of the events that took place. The Normandy invasion, also known as D-Day, was a major turning point in the war and marked the beginning of the liberation of Western Europe from Nazi occupation. Knight was a pilot during World War II and he wrote the book based on his own experiences and those of his fellow airmen.