Guest Stars Edward Fox as Assistant Commissioner Summers James McAvoy as Ray Pritchard Rosamund Pike as Sarah Beaumont Robert Hardy as Henry Beaumont Nancy Lodder as Tracey Stephens Sam Troughton as Second Policeman Cassian Horowitz as William Benedict Sandiford as Mark Andrews Jonathan Hackett as Doctor Joanna Kanska as Greta Beaumont David Horovitch as Thomas Kramer Tom Chadbon as Dr. Julian Groves Elizabeth Bell as Elsie Kramer Robert Goodale as Bob Keegan Robert Pickavance as Eric Stephens Andrew Powell as First Official Paul Putner as Second Official Neil Conrich as First Policeman Dominic Mafham as Michael Turner Philip Whitchurch as Ian Judd