Carey Mulligan is starring in the David Hare created drama that explores the spiraling repercussions surrounding the fatal shooting of a pizza delivery man. New cast includes John Simm (Life on Mars), Nicola Walker (Spooks) and Billie Piper (Doctor Who, Penny Dreadful).Set over the course of four days, the story centers on Detective Inspector Kip Glaspie (Mulligan), who refuses to accept that the murder is a random act of senseless violence and becomes determined to discover if there is a darker truth. Politician David Mars (Simm) instantly is embroiled in the drama through his turbulent relationship with his troubled and unpredictable ex, Karen (Piper). All the while, Jane Oliver (Walker), a compassionate vicar, struggles to conceal her affair with the only witness to the crime.