Four ordinary women with an extraordinary flair for code-breaking (despite it being 1952) and razor-sharp intelligence skills are the focus of ITV’s new murder mystery drama, The Bletchley Circle. They helped break codes used by the German military, wouldn't you know. Susan, Millie, Jean and Lucy have returned to their normal lives, but when Susan identifies a hidden pattern in a series of murders, she enlists the help of her former colleagues to crack the case. Starring Anna Maxwell Martin, Rachael Stirling, and Julie Graham.