Four extraordinary and brilliant women who worked at top-secret HQ Bletchley Park during World War II, are reunited for their second case in the first two-part story when a former Bletchley Park colleague  is accused of murder.

Jean played by the fantastic Julie Graham, methodically sets to work examining the evidence and is intent on helping Alice after a distinguished scientist is discovered shot through the heart in the study of his home with Alice, gun in hand, standing over him.

Jean calls on the ladies to reunite, but will they share her faith in Alice’s innocence?  Especially Millie, played by the super talented Rachael Stirling , the most modern of the girls – single, bohemian and adventurous…

“The Bletchley Circle” starts on Monday 6th Jan, 9pm on ITV1