"The Poison Sky" (which first broadcast on May 3, 2008) was directed by Douglas Mackinnon, produced by Susie Liggat and written by British screenwriter Helen Raynor.
Douglas Mackinnon Susie Liggat Helen Raynor Helen Raynor (born March 1972) is a British television screenwriter and script editor, best known for her work on the relaunched BBC science fiction series Doctor Who. 3 May 2008 (2008-05-03) 
