Idris Elba, Sean Penn and Javier Bardem have signed on to star in a film adaptation of Jean-Patrick Manchette’s novel, The Prone Gunman. According to Christian Blauvelt of Hollywood.com, “Elba will be playing a cloak-and-dagger agent named Dupont who tangles with Sean Penn, who also plays an agent for a clandestine operations outfit who is betrayed by his organization, forcing him on the run across Europe.”