In settings where there are long established underworld thief, criminal and otherwise ne'er do wells there is going to be a system of heraldry associated with those who live in and rule from the shadows.
There are gangs, there are biker gangs, there are terrorist organizations, and then there are the Sons of Scorpions
The PCs find a strange helmet, when donned it will take control of that PC and speak and act trough him/her. It explains that it is benevolent and needs their help in a quest and that it will stop possessing the PC when the task is done. Great if a player is gone for a number of sessions.