"The Blood Line" is the tenth and final episode of Torchwood: Miracle Day, the fourth series of the British science fiction television series Torchwood. It was first broadcast in the United States on Starz on 9 September 2011. Torchwood: Miracle Day follows the aftermath of a day where humanity has stopped being able to die. In the episode, a team called Torchwood seek to stop the "Miracle" affecting humanity's ability to die, which is engineered by a group of human families seeking to control the world.