Many of the 617 Squadron crews who took part in the famous attacks on the Mohne, Eder and Sorpe Dams and also the raids on the Dortmund-Ems Canal did not return. The book is illustrated with then-and-now photographs of the sites, the personnel involved and the aircraft originally flown.
Mostly useful if you're going to actually make the trip to Europe and want to visit some of the crash sites from Operation Chastise and the even more horribly botched Dortmund-Ems operation. The maps would be more helpful in color. Some minor mistakes in the text are jarring, but overall this clarifies some of the mysteries surrounding several of the lost aircraft.