THE SUNDAY TIMES BESTSELLER Two sisters, one war and an extraordinary family secret

1939. In the nation's hour of need, brave sisters Patricia and Jean Owtram answered the call of duty.

With their fierce intelligence and steely determination, these remarkable young women would stop at nothing to help crack the Enigma code, support Allied troops, and defeat the Nazis.

Their top-secret mission would finally see the tide of war turn in Britain's favour...

This is their incredible true story.