I was drawn to this series initially by the calibre of the cast. It stars Anna Maxwell Martin (who I adored in South Riding and The Night Watch), Rachael Stirling (Tipping the Velvet, enough said) and Julie Graham alongside a relative newcomer, Sophie Rundle. The four play women who worked at Bletchley Park during WWII but by 1952 they are leading mundane lives. That is until Susan (Martin) begins tracking the progress of a serial killer working his way around London (she has a collection of newspaper clippings tacked to the back of her bedroom mirror so that her husband doesn't find out). She spots a pattern in the killings and takes it to the police but, of course, they laugh her off. She feels she has no option to recruit the other girls for their various skills - Millie (Stirling), Jean (Graham) and Lucy (Rundle).
There are numerous twists in this one. Although we do catch sight of the killer 'at work', these moments mainly serve to heighten concern for the protagonists. They are four very clever women but they keep finding themselves stonewalled. When they finally do get the police to listen to them it becomes apparent that this may be bigger than any of them imagined.
The cast really were superb, though they were assisted by exceptional writing and wonderful period detail. The subject dictates that the drama should be dark and atmospheric and it succeeds. It offers a fresh twist on the period murder mysteries by introducing these four amateurs, all with different personalities and experiences since the end of the war. Intermingled with the suspense are snapshots of their lives - Millie quits her job in order to focus on the investigation while Lucy battles with her abusive husband. Susan, meanwhile, is pushing her own husband to his limits by refusing to tell him what's going on.
The Bletchley Circle succeeds on several levels, providing a tightly-plotted and compelling mystery drama that isn't a carbon copy of other programmes. I think it has potential to be a real hit and I hope that ITV have the courage to recommission it.