The Swarm is a type of space-borne organism which lived in the area near Saturn. It has traits of Earth-based viruses and was first encountered around 5000. The Swarm spreads by electrical pulses, which should make contact with the victim's eyes. When affected, the victim grows grey filaments around their eyes and hands and follows the swarm. There is no physical matter for the virus, which exists in a state in the mind/brain interface (though the nucleus has a crustacean-like form). This means the swarm can affect non-living sentients like robots and can have less of an effect on instinct-based individuals.
Certain people (such as Leela) have certain antibodies that can defeat the virus. As well, the virus can be slowed simply by not thinking.
Known Victims
- The Doctor (DW: The Invisible Enemy)
- K-9 (DW: The Invisible Enemy)
- Professor Marius (DW: The Invisible Enemy)
- Most of the Bi-Al Foundation (DW: The Invisible Enemy)