Set during the thrilling social change of the mid-1950s, THE BLETCHLEY CIRCLE: SAN FRANCISCO captures the lives of four remarkable women as they navigate various challenges, rekindle their capacities, and seek justice. Jean (Julie Graham) and Millie (Rachael Stirling) are brilliant codebreakers who, following their time serving at Bletchley Park during WWII, have rebuilt their lives in London. Drawn to the Pacific Coast by a string of murders that share grisly similarities to that of an old codebreaking friend, the two women find Iris (Crystal Balint) and Hailey (Chanelle Peloso), their wartime US counterparts. Gifted with extraordinary intelligence and a breathtaking genius for decryption, all grappling with the return to their mundane post-war lives of domesticity and unremarkable jobs, the women use their unique constellation of talents and do all in their power to uncover and stop a killer. Plunged into fascinating corners of the city, the four women forge influential relationships, rediscovering their own powers and potential. But with San Francisco being more dangerous than they could have imagined, will their intrepid team prevail?