Sunday night continues to be appointment telly on PBS tonight with the premiere of The Bletchley Circle. The three-part series follows the lives of several women who were code-breakers at Bletchley Park, the decryption facility that played a significant role in ending World War II. The four returned to civilian life following the war, but are reunited when a string of grizzly murders baffle the police and presents the ladies with a different sort of deadly pattern to solve.

Tonight’s episode begins during World War II showing the women as part of the U.K.’s code-breaking team that deciphered encrypted messages who also did other secret work for the Allies during World War II. Following the war, the Official Secrets Act prevents her and everyone at Bletchley from telling anyone, even her husband, that she worked at the facility. Unfortunately, the women’s incredible talents for spotting and breaking codes are buried during their post-war lives where their talents are soundly rejected by British society.
 

Watch Preview on PBS. See more from The Bletchley Circle.

Anna Maxwell Martin (South Riding, Bleak House) is brilliant as Susan, is an ‘ordinary’ housewife with extraordinary talents (and with two children), who has begun to collect data on a series of recent murders. After she unsuccessfully tries to convince the police that another is imminent, Susan gets the Bletchley Park band back together by reuniting Millie, Lucy and Jean to crack the murders and bring the culprit to justice. Putting her best Bletchley Park mind to work, Susan tells her old friends: “He’s making a pattern and he doesn’t realize he’s doing it. If we can crack it, we’ll be able to see what his next move will be. Just like knowing where the German army will be in three days’ time. We can get ahead of him and stop him before he kills again.”