As of 2014, there are two seasons of "The Bletchley Circle." The UK produced show most recently aired in the US on PBS between April 13 and May 4, 2014.
"The Bletchley Circle" focuses on four women who worked at Bletchley Park and actively broke codes used by the Germans during WWII. Set nine years after the war, former code breaker Susan is now a married mother. She still possesses the ability to see patterns during her day-to-day routine, and this skill comes into play when a serial killer begins murdering women in the London area. Susan turns to her past Bletchley Park colleagues Millie, Lucy and Jean in an effort to solve the puzzle and prevent additional murders.