At the village dance, the Family of Blood threatens Martha (Freema Agyeman) and Joan Redfern (Jessica Hynes) to get access to the Time Lord essence of the Doctor (David Tennant). Believing he is only a teacher named John Smith at a boys’ school in 1913, he is trying to understand what is happening. Student Timothy Latimer (Thomas Sangster) opens the watch in which the Doctor’s essence is hidden. When the Family is distracted, Martha grabs a gun and escapes with the others to the school. John organizes the school’s defences and Martha and Joan search for the watch.
An army of animated scarecrows attacks the school, but the boys have military training and hold back the first wave. When the family reveals it has the TARDIS, Joan accepts that John is really the Doctor. John, Joan, and Martha escape to an empty house in the village. Timothy finds them and returns the watch. The Family bombards the house from their spaceship. Martha and Joan beg John to become the Doctor and save them. He breaks down in tears, reluctant to give up Joan. They share a vision through the power of the watch, of what life would be like as simple humans growing old together.
The Doctor gains access to the Family’s ship, pretending his essence is still in the watch. He causes the ship’s power to overload and the ship explodes. He pushes the mother out into the event horizon of a collapsing galaxy, wraps the father in unbreakable chains, traps the daughter in mirrors, and suspends the son in Time forever as a scarecrow. He’s pissed. He offers to take Joan in the TARDIS, but she declines. Timothy says goodbye to the Doctor and Martha and is given the watch as a keepsake. Later, in World War I, Timothy remembers a vision of the bonding and avoids death. Many years later, he attends Remembrance Day with the Doctor and Martha.
David Tennant won the Constellation Award in 2007 for his portrayal of The Doctor/John Smith. Later, the Tenth Doctor would try to avoid regeneration because of memories as a human being. It rained for fourteen days when they were filming. Russell T. Davies thought the episode was too dark. Even as John Smith, the Doctor cannot shoot anybody. Joan points out that if the Doctor had not visited the school, none of them would have died. She also says that there could never be a black female doctor, but there was one in New England in 1865. The Doctor hid from the Family not because he feared them, but because he feared what he could do to them.