"The triumphant true story of the young women who helped to devise the winning strategy that defeated Nazi U-boats and delivered a decisive victory in the Battle of the Atlantic." -- From book jacket.

"By 1941, Winston Churchill had come to believe that the outcome of World War II rested on the battle for the Atlantic. A grand strategy game was devised by Captain Gilbert Roberts and a group of ten Wrens (members of the Women's Royal Naval Service) assigned to his team in an attempt to reveal the tactics behind the vicious success of the German U-boats. Played on a linoleum floor divided into painted squares, it required model ships to be moved across a make-believe ocean in a manner reminiscent of the childhood game, Battleship. Through play, the designers developed "Operation Raspberry," a countermaneuver that helped turn the tide of World War II. Combining vibrant novelistic storytelling with extensive research, interviews, and previously unpublished accounts, Simon Parkin describes for the first time the role that women played in developing the Allied strategy that, in the words of one admiral, "contributed in no small measure to the final defeat of Germany." Rich with unforgettable cinematic detail and larger-than-life characters, [the book] is a heart-wrenching tale of ingenuity, dedication, perseverance, and love, bringing to life the imagination and sacrifice required to defeat the Nazis at sea" -- provided by publisher.