Anna Maxwell Martin is to star in a new ITV drama about code-breaking, called The Bletchley Circle.
The three-part drama will also star Rachael Stirling, Sophie Rundle and Julie Graham and is set in the 1950s.
It follows four women whose skills at Bletchley Park during the Second World War helped break codes used by the Germans. In the programme, they continue to use these skills to help solve the murders of two women.
World Productions is making the drama, which will be produced by Jake Lushington and directed by Andy De Emmony.
ITV drama director Laura Mackie said: “The Bletchley Circle combines a vivid portrait of post-war Britain with a taut and original thriller.”