I have the interest. 

Stupid idea time: it's being discovered that within City X there are several shades under the guise of paladins killing them off, putting the paladins at risk of extinction within City X and forcing them to either kill their comrades hoping that they're shades after interrogation or something OR leave what you describe as a "tight-knit" group and live in solitude to save themselves.

Terrible I know, sorry.