The Unicorn and the Wasp

"The Unicorn and the Wasp" is the seventh episode of the fourth series of the revived British science fiction television series Doctor Who, which was aired on BBC One on 17 May 2008. Set in an English manor house in 1926, shortly before the disappearance of crime fiction novelist Agatha Christie (played in the episode by Fenella Woolgar), the episode is a murder-mystery storyline where a shapeshifting giant wasp, in disguise as one of the party guests, murders the other guests using methods similar to those in the novels of Christie, who is also a guest. Plot The Tenth Doctor and Donna invite themselves to a dinner party hosted by Lady Eddison in 1926. One of the guests is Agatha Christie, and the Doctor realises that they have arrived on the day she inexplicably disappears. One of the guests, Professor Peach, is killed with a lead pipe in the library, where part of a burnt birth certificate is found.