Set during the thrilling social change of the mid-1950s, THE BLETCHLEY CIRCLE: SAN FRANCISCO captures the lives of four remarkable women who previously worked as talented codebreakers during WWII. London based Jean (Julie Graham) and Millie (Rachael Stirling) are drawn to the Pacific Coast by a string of murders that bear remarkable similarities to that of a colleague during the war. Heading to San Francisco, they team up with Iris (Crystal Balint) and Hailey (Chanelle Peloso) to track down the murderer. Using their skills to investigate murders overlooked by the police, the intrepid foursome also delve into the mysterious death of a friend; get caught up in an underworld of secret communications; and become embroiled in a dangerous KGB plot. But can they survive the shattering consequences of coming face to face with their darkest, most calculating foe? Featuring all eight episodes.