Ghost cluster
From Tardis Wiki, the free Doctor Who reference
Ghost clusters were a type of weapon used by the Great Houses.
They were virtual bombs that were detonated in a model of the universe. When the probability of their detonation increased, the bombs' victims as well as their descendants became less likely to have existed. These victims were referred to as the walking dead.
They were deployed to erase any evidence on a planet of their interference. (PROSE: The Book of the War)
