Four ordinary women, heroines of this thrilling police drama, have a razor-sharp intelligence and an exceptional talent for deciphering codes. The Bletchley Circle follows the journey of four ordinary women with extraordinary abilities who helped end the World War II. In 1952, Susan, Millie, Lucy and Jean returned to their normal lives, leaving aside the role they played in producing the crucial intelligence that helped the Allies to victory and shortened the war. When Susan discovers a code hidden behind an unsolved crime, she is greeted by police skepticism. She quickly realizes that she can only begin to break down the crimes and bring the culprit with her former friends. The Bletchley Circle prints a vivid portrait of post-war Britain in this fictional story of uninvited heroes.