5 December 2015
Fleeing into the cloisters of Gallifrey’s Matrix, the Doctor and Clara find a Dalek shrieking “Exterminate!” But it wants to be exterminated. It’s one of a number of multiple aliens trapped in the Matrix, described by the Doctor as both “Sliders” and “Cloister Wraiths”. The Matrix is the biggest database in the universe and when something is stupid enough to break in, it gets filed against its will. Hence the Dalek’s death wish. The Doctor also suggests that the Dalek was “left over from the Cloister Wars” but we don’t learn anything else about this conflict.
