AIR DATE: May 26, 2007
VILLIANS: Family of Blood, Son of Mine, Daughter of Mine, Father of Mine, Mother of Mine, Scarecrow soldiers
ALIENS/MONSTERS: Scarcrow Soldiers, The Family of Blood
OTHER CHARACTERS: Joan Redfern, Jeremy Baines, Tim Latimer, Jenny, Mr. Clark, Lucy Cartwright, Phillips
LOCATION: Farringham, England; 10th and 11th November 1913
The Doctor and Martha narrowly escape an attack by the Family of Blood who are seeking the Doctor's Time Lord life force to prevent themselves from dying out. As the Doctor directs the TARDIS to Earth, he tells Martha that he must transfer into a human for three months to escape the Family's detection while they die, and gives her a list of instructions to follow. He then uses the Chameleon Arch to transfer his Time Lord configuration to a fob watch which he entrusts Martha to guard.
After landing on earth in 1913, a year before the Great War, the Doctor adopts the persona of John Smith, a schoolteacher at Farringham School for boys, while Martha acts his maid. John's personality is nearly opposite of the Doctor's, being quiet and timid, but faint memories of the Doctor slip through, appearing as text and images he writes in his "Journal of Impossible Things". Though John carries the fob watch, the perception filter that it possesses prevents John from being curious about it. John has become infatuated with the new school nurse, Joan Redfern, and shares his journal with her; Martha remains concerned as the Doctor did not instruct her what to do should he fall in love. Timothy Latimer, a younger student at the school with extrasensory perception, discovers the fob watch and pockets it for himself, unbeknown to Martha.
Meanwhile, the Family of Blood have been able to track the Doctor to Earth, and cover their ship in an invisible shield to keep it from being discovered. The various members of the Family seek out human victims to possess, including one of the school's prefects, one of Martha's fellow maids, a farmer, and a young girl with a balloon, allowing them to seek out the Doctor undetected. When Timothy briefly opens the watch and experiences portions of the Doctor's memories, the Family detects its presence at the school, and soon recognize Martha, trying to ply her for more information about the Doctor. Martha realizes that the Family has found them and attempts to retrieve the watch in order to bring back the Doctor, but cannot find it. She attempts to talk to John to awaken the Time Lord persona, but instead causes John to become angry at her, forcing her out of his chambers as he prepares for a village dance with Joan that night. At the dance, Martha again tries to persuade John to become the Doctor by showing him elements of his past such as his sonic screwdriver, but is unaware the Family has overheard her conversation. Now aware that John is the Doctor, the Family capture both Martha and Joan. The cliffhanger ending leaves the Family asking John the question of "Maid or matron, your friend or your lover. Your choice."