Led by 24-year-old Guy Gibson, pilots flew Lancaster bombers at terrifyingly low altitudes (60 feet) to drop "bouncing bombs" designed to skip across water and sink against the dam walls.
The author honors the genuine courage of the young crews, many of whom did not survive the high-risk, low-level flight into heavy enemy fire.
Hastings chronicles the obsessive work of engineer Barnes Wallis , whose unique bomb design made the "impossible" mission possible.