Rachael Stirling and Julie Graham star in this Bletchley Circle spin off set - as you can probably guess by the name - in San Francisco. The series follows two former code-breakers from the Bletchley park facility who, unsatisfied with the return to their monotonous lives as housewives post-World War 2, turn their hand to solving crimes overlooked by the police. Arriving in San Francisco, Jean McBrian and Millie Harcourt, played by Graham and Stirling respectively, liaise with two American code-breakers in pursuit of a serial killer from their war days. Set 3 years after the finale of the last season of the original show, the new series sees Jean and Millie living in the Californian city as they try to solve the murder of an old friend of theirs with the help of their new local partners Ivy and Hailey. Thousands of miles from home and in a completely new city and with new rules to abide by, just how will Julie and Millie adapt to their new lives and will they be able to solve the murder of their friend? The Bletchley Circle: San Francisco - Wednesday 9:00pm on ITV.