After the war, civilizations began to rebuild themselves, slowly but surely. The cost was great, but the people persevered hoping to one day regain their former homes. However, they didn't realize the war and destruction of several planets around their system had awoken a strain of virus. The wyrm, microscopic and virtually indestructible, travels through space, water, ground, whatever, until it finds a host in which to infect and multiply within. It leaves a circlesque mark somewhere upon the body that grows slowly as the infection spreads, and could almost be called beautiful but for the horrific side effects of the stigma:
The person will often experience pain and blackouts which occur more often as the infection spreads. During the periods of blackout the person has no control over their body or mind, and often they commit violent actions they are unaware of. Once the stigma has grown all over the body the host mutates into a vicious monster, one nearly impossible to kill.
There is no cure. Those that are seen to be infected are often quietly executed. There is no help, no hope, and no place to run. This is the Geostigma.