S1, E14: David Tennant, Billie Piper, Camille Coduri, Noel Clarke and Penelope Wilton star in this special which first aired in the United Kingdom on Christmas Day 2005. Written by Russell T. Davis, this is the first specially produced Christmas program in the history of the Doctor Who franchise. In the scary one hour special, Christmas has become a time of terror on Earth as all of mankind falls under the shadow of the sinister alien Sycorax.