How To Have Sex actress Mia McKenna-Bruce, 26, leads the cast as the young sleuth Lady Eileen “Bundle” Brent, who appeared in the novels The Seven Dials Mystery and The Secret Of Chimneys. She is joined by two-time Oscar-nominated actress Bonham Carter, 58, as Lady Caterham and Sherlock star Martin Freeman as Superintendent Battle, a character who was in various Christie books including in Hercule Poirot mystery Cards On The Table. Mia McKenna-Bruce (Netflix)A first-look image shows McKenna-Bruce, a Bafta rising star winner, sitting on the floor in a black dress while reading The Seven Dials Mystery and surrounded by clocks. Bundle is set to step in to try to solve the mystery, changing her life. The Seven Dials Mystery will begin filming this summer.