Lead by a shadowy being known only as The Faceless One, the Serrated Query appears to be a clandestine criminal organization that exists sorely for the purposes of making a profit without thought of morality or conscience. The group actively promotes conflicts throughout the Imperium, making proceeds by selling information and resources to all sides involved. The Serrated Query also engages in smuggling, drug trafficking, slavery, extortion and the movement of Xenos goods. The Serrated Query has been in existence for thousands of years and some in the Inquisition speculate that in order for the Serrated Query to still exist, despite several purge attempts to eradicate it, it must have ties to powerful organizations in the Imperium- possibly even the Inquisition.
The Serrated Query were behind a drug ring on Scintilla that was making Farcosia, a drug made from the brains of psykers, among other things. They have been known to use xenos technologies and xenos mercenaries. See dossier on Theodosia for more information.